Lisbon is a large and welcoming city with churches, monasteries, palaces and fortresses, some dating back to the 11th century. It’s the city of seven hills, although it seems like more because almost everywhere you turn there seems to be a hill or a staircase. When it comes to food, seafood is in the spotlight, including fresh, salted and canned varieties, as well as pork, soups like caldo verde and various rice dishes, all of which can be accompanied excellent, very affordable Portuguese wines.

If, like me, you have a sweet tooth, there is no nobler goal than the delicious and ubiquitous pastel de nata (pronounced pash-tell de nah-ta; plural are pastais de nata). These little tartlets feature a rich egg custard surrounded by a crisp, flaky crust. Because the tartlets bake in a very hot oven, the custard becomes speckled dark brown on top.

In addition to tasting “nata” in the city, I took a pastel de nata baking class. (There are many courses offered on the subject, but the one I took was at Homecooking Lisbon through Viator.) Unsurprisingly, custard is a fairly simple mixture of egg yolks, milk, sugar, cornstarch and/or flour to thicken, and flavorings, such as lemon, vanilla and/or cinnamon. The sweetener comes in the form of a liquid, a simple syrup made from sugar and water. Our teacher, Carolina Gomes, said that although nata means cream in Portuguese, there is no cream in the recipe, just whole milk. (Although there may be recipes that call for cream.)

The dough is the trickiest part of the equation. It is a puff pastry, just like croissants and puff pastry, to create many, many layers that separate and become crispy while baking. In our class, we worked with a simple dough made from flour and water (and a pinch of salt), rolled it out into the shape of a four-leaf clover, and placed a thin slice of… gasp! …margarine in the center. While many pastel de nata recipes contain butter, Gomes assured us that margarine is often used. One reason is that margarine is made from vegetable oils and may have a lower water content than butter, unless the butter contains a high fat content of 80 to 90 percent. Cost is likely a factor that prompts some bakers to choose margarine.

After the dough is folded over the margarine (or butter), it is spread again and repeated several times, so that the fat is captured between several layers of ultra-thin dough. It is then rolled into a tight jelly roll and cut into ½ inch wide spirals. These are pressed into small metal molds, using your thumbs, to completely line the inside of the cups. The molds are placed on a baking sheet and the custard is poured into each dough-lined mold almost to the top. The tartlets bake in a very hot oven (500 degrees Fahrenheit or higher) for about 10 minutes or until the custard is golden and the crust is dark golden brown.

The custards I tasted at most pastelarias had a slight vanilla flavor (some tasted very slightly like rummy). The texture can vary from thick to gooey. The best stores make their pies throughout the day, so at any given time there may be batches of pastries out of the oven, warm and at room temperature. You should not eat them cold. Nor hot, which would burn the palace. I prefer room temperature to very slightly warm nata. I like custard creamy and velvety and slightly thick, but not too firm, and definitely not too gooey.

Although the custard may vary from place to place, there is only one way to prepare the pastry. The crust should be nicely browned and you should see the many layers of dough (like phyllo and mille-feuille) along the edge of the pie. It should be very crispy and break into flakes when you take a bite. Flip the nata over and you should see the swirl of layers of dough at the bottom. The bottom should also be crispy. If it’s soft or soggy, that means the pie has been sitting too long or perhaps undercooked.

Before sharing my favorites, here’s a little history of the famous tarts: Portugal has a long and extensive pastry tradition, much of which was created in monasteries and convents. Egg whites were used to starch clothing, especially nuns’ habits, which meant there was a lot of egg yolk left over. Once sugar became widely available, the yolks were used to make custards and other treats. Pastries like pastais de nata were sold to raise money for convents and monasteries, and fundraising became especially important after the liberal revolution of 1820. The recipe was later sold and the tarts were produced on a large scale. much larger at Antiga Confeitaria de Belem, established in 1837, now simply called Pasteis de Belem. (The store is said to make 20,000 pies a day, and almost double that in summer.) Other Portuguese bakeries have started making their own versions, but only those from the original bakery, whose recipe is a secret well kept, can be described as “Pâtéis de Belém.”

So I set out, armed with a list of a dozen pastelarias and a goal: to tackle two to three pastries a day. In the end, I liked most of the nata I tried, but some were slightly better than others for my taste. (Prices range from 1.3 to 1.55 euros – less than $2 – for a pie.)

My favorites were the nata de Manteigaria and Fabrica de Nata. The “original” pastries at Pasteis de Belem (rua de Belem, 84) were also very good but the store had the longest lines and an assembly line-like process. Without tasting the tartlets side by side and at exactly the same temperatures, it’s difficult to compare them. La nata de la Pastelaria Versailles (Av. da Republica 15A) was slightly different from the others; they were a bit larger with a slightly smaller circumference and the custard was thicker and firmer. (You can stop at Pastelaria Versailles if you head north to the excellent Calouste Gulbenkian Museum, but I found it not to be the most foreigner-friendly place.)

Manteigaria has eight “factories” in Lisbon; Popular spots include Rua Augusta, 195-197, Rua do Loreto 2, and the bustling Time Out Market (Ave 24 de Julho). On his website, Manteigaria states that “butter is a fundamental ingredient in our pastel de nata,” hence the name of his company, as butter is manteiga in Portuguese. (We can assume that Manteigaria uses butter and not margarine in its dough.)

Fabrica da Nata, located at Rua Augusta 275A and Praça dos Restauradores, 62-68, has a glass wall in front of its stores so you can see the bakers assembling the pastries and watch the brown-speckled nata molds come out of the oven . Confeitaria Nacional is a charming, almost two-century-old cafe located at 18B Praca da Figueira, with indoor and patio seating in the square.

Although not an exhaustive list, other bakeries worth visiting if you are in their area include two centrally located cafes on Rua Garrett, Pastelaria Benard (104) and Castro (38); Pastelaria Cristal (rua de Buenos Aires 11); Pastelaria Santo Antonio (rua do Milagre de Santa Antonio 10); and Pastelaria Aloma (Largo do Calhariz 3). Note that you’ll see custard tarts in all kinds of cafes, but not all of them are made on site. Save your nata eating for the real pastelarias.

In most cases, you will find on the counter or delivered with your nata a cinnamon shaker and sometimes one with powdered sugar. A pinch of cinnamon adds a pleasant nuance that I recommend you try. There is no need to add more sugar.

If you’re heading to Lisbon anytime soon – but there’s no rush, because these pastries have been around for 200 years and they’re not going anywhere – put on those comfy shoes and go in search of the best pastais de nata in town. If you climb a few hills on your way, you can treat yourself to several.

Lisa Zwirn can be contacted at [email protected]

Lisa Zwirn can be contacted at [email protected].