Leche frita — fried milk custard with sugar and cinnamon

Prepare a square metal dish with internal dimensions of about 18 × 18 cm and sides at least 4 cm high. Line it with parchment paper extending above the edge, without adding fat. Weigh 150 g cold milk into a bowl. Pour the remaining 600 g into a heavy-bottomed saucepan and add the 90 g sugar, cinnamon stick and strips of yellow lemon zest. Heat until steaming strongly with the first bubbles around the edge. Take off the heat, cover and leave for about 10 minutes, then remove the cinnamon and zest. Do not add lemon juice.

Add all the cornstarch to the reserved 150 g cold milk and whisk thoroughly until no dry lumps remain. Briefly reheat the infused milk until steaming. Stir the starch mixture again just before pouring, because it settles on the bottom, and pour it into the saucepan in a thin stream, stirring without stopping.

Cook over medium-low heat, whisking vigorously across the bottom and around the sides. The mixture will thicken quickly. Once it starts bubbling clearly, reduce the heat and cook for a full 3 more minutes, stirring constantly so the starch cooks thoroughly and the mixture does not stick. The finished mixture should be smooth and very thick, leaving a clear trail behind a spatula. Take the saucepan off the heat, add all 15 g butter and stir until incorporated. Immediately transfer to the prepared dish and level into a layer about 2.5 cm thick.

Press plastic wrap suitable for hot food directly onto the surface. Leave for about 15–20 minutes, until it stops steaming strongly, then refrigerate for at least 4 hours, preferably overnight. Do not leave the dish on the counter until the next day. Before cutting, the mixture must be completely cold and firm enough for a lifted piece to hold its shape. If it is still soft, chill longer rather than trying to fry it.

Lift out the cold mixture using the paper and gently peel it from underneath. Cut the whole slab into sixteen squares about 4.5 × 4.5 cm, making four pieces in each row. Do not separately trim the edges. Put the weighed flour in one shallow plate and thoroughly beat the two eggs in another. Lightly dust each cold square with flour on all sides and shake off the excess. Then dip in egg and let the excess run off. Coat only a few pieces at a time, just before frying; keep the remaining milk custard squares in the refrigerator.

In a deep frying pan about 20 cm across, heat 500 g oil to form a layer about 1.5–2 cm deep. The oil should be hot but must not smoke: a drop of coating should immediately be surrounded by small bubbles and gently float up, without darkening immediately. Carefully add three or four pieces, leaving space between them. Fry over medium heat for about 1–2 minutes on each side, turning gently with a wide spatula or slotted spoon. The coating should be evenly golden, with no raw egg on the surface. Wait briefly between batches for the oil to heat up again and remove loose bits of coating.

Lift out the fried pieces, supporting them from underneath, and place in a single layer on paper towels for about 1–2 minutes. Mix the 60 g sugar with all 3 g ground cinnamon in a shallow plate. While still warm but no longer dripping oil, gently roll the pieces in this mixture and shake off the loose excess. Do not apply thick additional layers. Unused flour, beaten egg, oil and cinnamon sugar are excluded from the servings; discard leftover coating ingredients that have come into contact with raw egg.

Serve immediately, two pieces per person, without extra sauce, cream or fruit. The center should be soft and milky, and the coating thin and golden. Do not pile hot pieces in a tall stack so the coating does not become soggy from trapped steam. If any remain, let them cool briefly, then transfer to a lidded container and refrigerate; eat within 24 hours. Leftovers can be served cold, allowing for the coating to soften.