Tokyo: this world-class metropolis is a veritable gourmet wonderland.

Discover the stories behind the ingredients that make this city so delicious - so "oishii."

Our focus today is shiitake - the global star of Japanese mushrooms.

It's a key ingredient in all kinds of Japanese dishes, from boiled to fried.

Shiitake cultivation is said to date back at least 400 years.

These days, shiitake is loved all around the world.

Even in Sweden, where our reporter Janni's from.

Her brother joins us to cook a local favorite using shiitake!

- Do you want some?
- I would love some. Stop it!

Discover the hidden charms of the feast of the forest - shiitake.

Trails to Oishii Tokyo.

Hello, everyone.

My name is Janni Olsson, and the theme of today's show is shiitake.

Now, Swedish people love mushrooms.

It's almost considered a national sport in Sweden to go out and pick your own mushrooms in the forest.

In the fall, we like to go out mushroom picking!

It's like a treasure hunt.

People look for them earnestly.

Aromatic mushrooms called chanterelles are most common.

So it's going to be interesting to see how shiitake compares to the mushrooms I loved eating growing up back at home in Sweden.

Let's find out! Come on.

Her journey begins in Toyosu, a hub for Japanese food products.

She'll speak with a wholesaler to find out more about shiitake.

- Hi, I'm Janni.
- I'm Tomoda.

Nice to meet you.

- Looking for something?
- Shiitake.

- Are they here?
- These are shiitake, yes.

You have several types?

Different types, different production areas.

Shiitake are usually cultivated one of two ways.

These are grown in fungi beds.

Fungi beds contain solidified particles like sawdust or rice bran.

Shiitake grown in beds are tasty and low-cost.

They usually cost about 50 cents a piece.

These are log-grown shiitake, commonly grown on broad-leaf trees.

Depending on the season, they're anywhere from one to two dollars a piece, and they're super tasty.

This pack is ten dollars.

In Sweden, we only have mushrooms in the fall.
Can you get shiitake all year round?

Fungi beds are year-round.
Log-grown shiitake are roughly October to March.

So winter is a good time for shiitake.

Good products come in January and February.

I recommend trying some
if you have the chance.

That's the plan!

Her next stop is Kagurazaka, Tokyo, home to many well-known Japanese restaurants.

For this restaurant specializing in traditional cuisine, adding shiitake to the winter menu is a must.

Owner Komuro Mitsuhiro has something special in store for Janni.

This is "chawanmushi." Enjoy.

Popular in winter, chawanmushi is a steamed dish usually containing eggs and dashi broth.

The "yuzu" citrus, wild parsley and shiitake aromas will make your stomach growl.

Okay. Here we go.

This is excellent.

Subtle aroma.

A light flavor with an invigorating aroma.

Right, it kind of wakes you up.

Next is a dish that brings out the shiitake's umami.

Minced kuruma shrimp are spread on, and they're fried in oil.

The synergy of the shrimp and shiitake umami create outstanding flavor.

That's a great combo!

I thought the shrimp would overpower
the shiitake, but that's not the case.

Shiitake hold their own in terms of sweetness,
aroma and umami.

Adding shrimp enhances the flavor even more.

Komuro says dried shiitake is a great way to enjoy the mushroom's umami.

These are high-quality shiitake
that've been dried.

Drying produces an umami compound called guanylic acid.

When rehydrated, they contain ten times the umami as when fresh.

Boiling for 30 minutes makes a dashi broth that's packed with umami.

Dried shiitake dashi.

The foundation of umami in Japanese cuisine.

He lets Janni have a taste.

Try some.

"Itadakimasu."

"Oishii." Great flavor.

- Only using shiitake?
- Right.

All this flavor just from shiitake.

Dried shiitake broth is often used for "ni-mono," or simmered dishes.

This is "chikuzen-ni" - dried shiitake, burdock root and carrots are simmered together for a deep flavor.

This is amazing.

Simple, but packed with flavor.

In Japan's mushroom world,
shiitake probably make the best dashi.

Dried shiitake have exceptional flavor.

I think they make the tastiest broth.

I'm learning a lot about shiitake.

They're quite interesting.

Dashi from mushrooms, and all that umami!

What a surprise!

To see how they're grown, Janni heads to Izu, Shizuoka, 150 kilometers west of Tokyo.

With a mild climate and lots of rain in the fall - perfect for mushrooms - the area is one of Japan's major shiitake producers.

Janni's on her way to a long-established shiitake farm.

- Good morning.
- Morning.

Wow. Is this your farm?

Rows of about 35,000 logs are seen all around!

Each one is fostering fungi that'll grow into shiitake.

Not what I was expecting.

I thought there'd be a big fallen tree
with mushrooms growing on it.

Guess not.

We cut logs, plant fungi in them,
and prop them up like this. All by hand.

Suzuki Masaya is the 4th generation head of this 100-year-old farm.

His cultivation method has been passed down over generations.

It's a form of log cultivation.

He uses sawtooth oak and oak trees from nearby mountains.

This is called "tanekoma."

It contains shiitake fungi.

They're hammered into logs that are each about a meter long.

The logs are stacked in a place that gets good air flow, so the fungi can grow well.

They're left for about a year and a half.

Lining them up this way exposes shiitake to natural elements like rain and fog, helping them grow.

About two years pass from planting to harvest.

Why does it take so long?

In log cultivation, the fungi need time
to decompose nutrients from the wood.

So, it takes longer.

Log-grown shiitake taste good because
they only eat nutrients from logs.

Also, they have to break through tough bark.

That also lends to their high quality.

- They're like victors in a tough competition.
- Cool.

It's time for Janni to pick some.

The gills under the caps are sensitive.
Touching them damages the shiitake.

To avoid this, we grab carefully from the top.

I see.

The less they're touched, the better.

Can I try?

- Yes, of course.
- Nice!

- Like this, right?
- Yes.

Ah, nice and easy.
It comes right off.

It really smells like forest.

Searching for mushrooms in a forest in Sweden isn't this easy, so this is fun!

This place would be a hit in Sweden.

You'd get lots of unannounced visitors!

Log-grown shiitake have strong umami.

Most end up dried, so they keep longer.

Drying them soon after harvest retains all their flavor, which means tastier dashi.

The dryer is kept between 40 and 56 degrees Celsius.

The shiitake stay in for 36 hours, reducing moisture to around 10 percent.

Dried shiitake packed with umami - thanks to the nutrients they absorb from logs they grow on.

Shiitake cultivation is closely linked to conservation.

When fall hits, Suzuki heads to the mountains to cut down trees for growing shiitake.

A sprout appears from the stump and grows into a full-sized tree over the next 20 years.

It's the circle of life.

This cycle of cutting and cultivating maintains the health of the forest.

How nice. Taking care of the mountains
ensures healthy shiitake to grow.

It's a lovely coexistence.

- Right. It's all connected.
- Yeah.

People here have enjoyed these mountains
their whole lives. We came here as kids.

We understand how special this wood is.

This area will be lush again for
the next generation.

And future shiitake farmers will
be out here cutting like I am now.

Hopefully we can conserve the mountains
in that way for years to come.

Lovely.

How do locals enjoy shiitake?

Janni visits a shop operated by a shiitake farm.

What's the best way to enjoy shiitake?

Grill both sides, and simply add
a bit of soy or other sauce.

Soy sauce, nice.

Freshly-harvested shiitake are perfect on the grill.

As they heat up, moisture containing flavor compounds is released.

With so much umami, a dash of soy sauce is all you need.

- "Itadakimasu."
- Enjoy.

- It gets really juicy.
- Right.

- Very nice aroma!
- I agree.

Because it's still fresh.

We have children stay here who usually hate shiitake,
but they enjoy ours, which pleases their parents.

I guess picking shiitake
makes them more excited to eat it.

How nice.

- Is that for me?
- Yes. Enjoy!

Next up is "chirashi sushi," a regional celebration food.

Dried shiitake simmered in soy sauce and sugar go over rice along with carrots, tuna flakes and egg.

Very good!

We make this for parties or for guests.
It's great for picnics too.

- It's elegant.
- Yes.

Definitely good for a picnic.

I see, so shiitake is good for special occasions too.

So good.

I'm glad you like it.

I've had so much fun.

Shiitake grown with passion.

Nothing beats fresh mushrooms.

Ta-da!

Actually, a lot of people are growing shiitake at home these days.

Growing kits with sawdust blocks containing fungi are readily available.

Anyone can do it.

Soak your block in water, and spray it daily with a water bottle.

Do this for about five to seven days until shiitake appear.

They're fun to grow, and they taste fresh!

The kits got really popular after people got stuck at home during the pandemic.

It's easy for kids to do too.

Parents report back that their kids
have fun checking the shiitake daily.

Janni stir-fries some in garlic butter and soy sauce.

Whipping up a tasty homemade meal with shiitake grown at home?

What a treat!

Shiitake have taken the world by storm.

Even in Janni's native Sweden, raw shiitake are easily spotted in the produce section.

How are they used?

Janni's brother, Christian, who's based in Norway, will clue us in.

- Hi.
- Hello. Hi.

How you doing?

- Very nice, and you?
- Yeah, yeah. It's kind of warm over here.

By the way, did you find any shiitake?

- We have these ones.
- Ah, okay, so they are fresh ones?

Oh, yes. Oh, yes.

But isn't the season over in Sweden now for mushrooms?

Shiitake cultivation has been expanding around Sweden over the past decade, allowing fresh shiitake to be had all year around.

The Swedes love mushrooms, and umami-packed shiitake are no exception.

Let's cook with it and see, like, if it's any different.

Like... you're doing something very Scandinavian but on, like, Japanese mushrooms.

It's going to be interesting to see, like...

Yeah, it'll be nice.

- I think it'll be pretty good.
- You think it's gonna be good?

- Yeah, yeah, I think.
- Okay, let's do it.

- I'm not gonna help you, but go ahead.
- Oh, I know!

But that is usual.

Christian will make a mushroom cream sauce, a local favorite.

He says more and more people are cooking with shiitake these days.

First, saute the shiitake in butter.

Season with salt and pepper.

In Swedish cooking, it's important to give all the flavors room to breathe.

Add chopped garlic and onion to boost aroma.

This will have to just stand and fry, like, on semi-hot for a while, and then add cream, cream, cream and cream,

and just boil it together until it's the way we want it.

So, cream, cream, cream. Okay.

Yeah. Cream, cream and cream.

Yep. Scandinavian mushroom dishes: cream, cream, cream.

Cream poured over mushrooms - a common sight in a Swedish kitchen according to Christian.

That looks so good.

The cream takes in the umami, producing a rich flavor.

A common main dish is baked cod.

He'll serve it with the shiitake cream sauce.

Ah, nice!

That looks really soft. Nice.

Here it is!

Oh, that's definitely going to be good.

Shiitake in Swedish food!

- Do you want some?
- I would love some! Stop it!

It looks so good!

I wonder how it tastes!

Thank you.

Good?

It's mostly the texture that is a lot firmer than the mushrooms around here.

So I can imagine that you use these a lot in soup because they can probably boil or be in the soup for a long... long time without being smushy and soggy.

That was... that's a very big difference. Very nice.

How about a flavor like... I know especially, like, in Japan it's kind of famous for having, you know, a lot of umami, and use it usually to take, like, dashi. You know?

In Japan, like, for a soup, having the base because it has so much flavor...

That is definitely the...

That is definitely the profound... You can definitely feel the taste.

That's... I have now onions and garlic and salt, pepper.

There is a lot of taste in the... there's a lot of taste in these ones.

Yeah, I'm really glad to hear you can actually combine this with the dishes I like from Sweden with mushrooms, like you can just switch it up for shiitake instead and get a new variation of it.

Well, then, you can make it for me when I come home next time.

Yeah, yeah...

Maybe you will make it.

I will do the toast and you will do the main.

- Okay. Together.
- Okay.

Thank you so much for today.

- Bye!
- Thank you very much.

Yay. See you in a couple of months.

Yes, bye.

I can't wait to eat Swedish shiitake!

Janni's final stop is Roppongi, an area of Tokyo with many high-end restaurants.

One French restaurant has received non-stop praise by foodies for 11 years.

The chef's special has shiitake in it!

Iizuka Ryuta felt shiitake was the right choice for a French dish catered to the Japanese palate.

He cuts carefully-selected shiitake into thick slices, to accent their texture.

Then, he fries them in butter, making them nice and rich.

He preps a traditional sauce made of white mushrooms, shallots, pancetta, and other ingredients.

The secret ingredient is finely-chopped dried shiitake.

They provide intense umami.

Water left over from rehydration is added to enhance aroma.

The mixture is placed over a pie crust...

and topped with sauteed shiitake.

The flavors are locked in with a sheet of pancetta.

Shiitake powder and pork sauces are drizzled on top.

The aroma, texture and umami of shiitake are front and center.

Iizuka put his French cooking skills to use in creating something truly unique to his home country.

Wow. "Itadakimasu."

"Oishii."

- Amazing. Shiitake is the star.
- Absolutely.

I never considered shiitake in French food.

In Europe, everyone's all about truffles,
but shiitake could bring some competition.

Right.

Most people think of shiitake
as simply a cheap ingredient.

But price doesn't matter.
The real value is in its flavor.

Of course, a lot of that comes from
the hard work of growers.

I want to reflect that passion in my dishes.

I'd never get bored of this.

I'll definitely be back.

Some people have been back
to eat this like 20 or 30 times.

Not surprised. I'd be here every day
if I lived around here.

Shiitake are very different from the mushrooms we have in Sweden.

There's huge amount of love and care that goes into growing them, which makes them packed with flavor.

I hope shiitake continues to grow in popularity around the world.

In Tokyo, every ingredient has its own story.