Pastel de Belém (Portuguese Custard Tart)

Dough

1. Weigh the flour; don't measure it by volume. Combine the flour (250 g2 cups) and the salt (3 g½ tsp). Add 100 ml7 tbsp of the cold water and mix until a shaggy mass forms. Add more water a tablespoon at a time, only as needed, until the dough comes together into a cohesive, slightly tacky ball that pulls from the sides of the bowl. Don't add all the water at once.

2. Knead 1 to 2 minutes, just until smooth. The dough should be soft and pliable, not sticky. Shape it into a rough square, dust with flour, wrap in plastic and rest 15 to 30 minutes at room temperature.

Fat

1. Leave the butter at room temperature until very soft, like room-temperature cream cheese. This is a soft lamination, not classic puff pastry: the butter goes on with a small offset spatula or the back of a spoon.

2. Divide the butter into 3 equal portions, about 78 g each.

Laminate

1. Chilling. Refrigerate the dough 15 to 30 minutes between folds so the butter stays put.

2. First fold. Roll the dough into a thin rectangle of about 18 × 12 inches, long side toward you. Brush off excess flour. Spread one portion of butter over the right two thirds of the surface, leaving the left third bare and a small border all around. Fold the bare left third over the middle, then the right third over the top, for 3 layers. Press the edges gently to seal.

3. Second fold. Turn the dough so the folded seam faces you. Roll it out again to about 18 × 12 inches. Spread the second portion of butter over two thirds of the surface and fold the same way.

4. Final roll. Turn the dough so the seam faces you again. Roll it into a large rectangle of about 20 × 18 inches, short side toward you. Spread the last portion of butter over the entire surface. Starting from the edge nearest you, roll the dough away from you into a tight log, brushing flour off the underside as you go and stretching gently to keep the spiral compact.

5. Trim the ends, cut the log in half and wrap tightly in plastic. Refrigerate at least 2 hours, ideally overnight.

Custard

1. Whisk the potato starch (25 g) with the whole milk (60 ml¼ cup) and the fine salt (1.5 g¼ tsp) until smooth.

2. Combine the sugar (250 g1¼ cups), water (150 ml½ cup + 2 tbsp), cinnamon stick and lemon peel in a saucepan. Bring to a boil and cook without stirring to 104°C (220°F), about 3 minutes. Take out the cinnamon and lemon peel.

3. In a separate pan, bring the whole milk (240 ml1 cup) to a scald: steaming, with tiny bubbles at the edges.

4. Pour the hot milk into the starch paste, whisking briskly until smooth and thickened. Then pour in the sugar syrup in a thin, steady stream, whisking constantly.

5. Let it cool until warm but not hot; you should be able to hold your hand comfortably against the bowl. Whisk in the egg yolks (6). The custard should be thin, like heavy cream. Strain through a fine sieve into a jug and cover with plastic wrap touching the surface.

Shape and bake

1. Heat the oven to its maximum, 270–290°C (520–550°F), in standard mode rather than convection, with a pizza steel or stone on a lower rack and a baking rack in the upper third. Preheat at least 30 minutes.

2. Shape the shells. Slice the chilled log into rounds ⅝ to ¾ inch thick. Set each one cut side up, spiral showing, in a pastel de nata mold or muffin cup and rest 5 minutes. With thumbs dipped often in cold water, press each disc outward and upward to line the cup, until the dough reaches just above the rim, with the edges slightly thicker than the base. Aim for nearly translucent at the base.

3. Fill and bake. Fill each shell three-quarters full. Bake 10 to 12 minutes in standard molds, or 8 to 9 minutes in mini muffin tins, until the pastry is deep golden and the custard has dark blistered spots. The custard should still wobble when it comes out.

4. Serve. Take the tarts out of the tins immediately; they stick if you wait. Cool on a wire rack for 5 minutes, then dust with ground cinnamon and powdered sugar. They are best within 20 minutes and should be eaten the same day.