in pretty much every bakery in Portugal.

Pastéis de nata are beloved in Portugal

the same way croissants are in France.

And while tons of bakeries around the country

make pastéis de nata, the original version is made

using a 100-year-old secret recipe.

So how did these tiny tarts

become such a big deal here in Portugal?

Well, the answer is right here,

at the Monastery of Jerónimos.

It is here that their story began,

because monks used to be

the very first people to make the tarts.

But thankfully for us, the recipe didn't stay locked

in the monastery with them.

A bakery nearby inherited it,

and six generations later, it's still there.

The pastéis you'll find all around Portugal

are called pastéis de nata,

but at this bakery, they're called pastéis de Belém.

Belém refers to this neighborhood,

where the tarts were invented,

and no other bakery is allowed

to use this name for its sweets.

There are two reasons why the pastéis

at this bakery stand out.

The first one is their pastry:

extremely flaky, slightly salty,

and with a signature crunch.

[pastry crunching]

The second is their egg custard:

more delicate, light, and not too sweet,

which make these an ideal snack for anytime of the day.

To preserve the ancient recipe it inherited

from the monastery, the Lisbon bakery

keeps its pastry and custard recipes secret.

Penélope: This is the secret part of the recipe

that is made inside.

Only four people work with the recipe.

These are four people that we trust very much

and that do this amazing work every day.

Claudia: So, how many people in total know the recipe?

In here, but I guess in the world?

Penélope: Seven.

Claudia: From here, we don't know exactly what happened,

but we can see that the dough is pretty wet.

This is because of the egg yolks?

Penélope: You can guess.

[both laugh]

Claudia: And then this dough will then be turned

into little pasties. Penélope: Yes, yes.

Claudia: OK, let's go see it.

Penélope: We do it all with our hands.

That is a big part of the secret.

Claudia: When she goes in there and cuts it,

inside you can see the little layers.

Penélope: You see outside,

when it's cooked, you see them separating.

Claudia: Still, I imagine there's still a lot of work

with the dough. You have to create your layers,

and alternate, and laminate with the butter.

It's just a testament of what is happening

in that secret room.

And how many pastéis would you get

out of one pice of dough like this?

Penélope: OK, 180.

Claudia: After being stretched,

the little pieces of dough are placed in individual molds.

Luísa and her colleagues go through

over 22,000 of these a day.

In this room, it's only about

shaping the dough. Penélope: Yes, yes.

Claudia: Wow. OK, so then they must have

very strong thumbs here.

Penélope: Yeah.

Claudia: So, you just move it like this. Yeah?

Penélope: Press it. Claudia: Press it.

Penélope: And then bring it out.

Claudia: Bring it out.

Basically what you want to do is not have it too thick.

If you don't know what you are trying to get,

if you don't know how thick the dough is to start,

you can't just go in and, like ... [laughs]

But yeah, there's lots, lots, lots of butter.

Time to wash those buttery hands

and try to reveal another secret, the egg custard.

We don't know for sure, but during my research,

a lot of sources mentioned how

this custard is made with milk, not cream,

to make for a lighter and less sweet custard,

which is meant to better complement

the salty flavors of the pastry.

But we know that there are egg yolks inside, right?

This is not a secret.

Penélope: Yes, I can tell you that, yes.

Actually, not only the pastéis, but many sweets

that are made in Portugal have egg yolks,

because in the convents, the nuns used the egg whites

to iron their suits and left the egg yolk,

and then used it to bake sweets.

The monasteries were not as we think now,

a place where people were only praying.

Actually, they were places of commerce.

In here, in Belém, we had

the caravels that came from Brazil,

and it was really full of people.

Claudia: So, what do you think?

Is it the pastry dough, or perhaps the egg custard

that makes these tarts different from the rest?

Penélope told me the way to get this caramelized look

is to bake the tarts in the oven at 400 degrees Celsius

for about 20 minutes.

Penélope: And the pastéis are getting married.

They put the two together,

and they are ready for leaving.

Claudia: OK, and why do you do that?

Why do you put one on top of the other?

Penélope: Because they protect each other,

and together they are stronger.

Claudia: OK, I see.

And then when you go and sell them, though, you have to ...

Penélope: No, no. They go together.

Claudia: Oh, they always go together.

Penélope: Yeah, well, unless you have only one.

Claudia: And just like you would join a married couple

at their reception, I can't help but join these two pastéis

in the bakery's cafe for a little tasting session.

Penélope: Finally, we got to this part,

which is the best part.

Claudia: Of course. It's always the best part.

Penélope: And so now, the pastéis go with the cinnamon

that came in the caravels.

And then sprinkle with a little bit of sugar,

and now they are ready to eat.

Claudia: So you don't put any lemon, or ... ?

Penélope: No. No lemon.

[pastry crunching]

It's so crunchy.

It's actually very delicate as well.

I really love the cream.

You were saying, the egg yolks, and there's lots of eggs,

so you would expect heavy cream,

but this is amazing because it's very, very delicate.

Lots of layers.

Penélope: We know when the pastéis is good

by the sound of it.

[pastry crunching]

They are not very sweet. They are very balanced

and have the salty of the outside,

and then the sweet from the inside.

Claudia: So, these two pastéis,

they were married, and now ...

Penélope: They are divorced.

Claudia: I have to have another one.

Nicola: Just, like, walk and look at them.

[laughs]