Steps

• Place the milk with the lemon zest (without the white pith) in a saucepan, set it over the heat and warm the milk until it almost reaches a boil.

  Meanwhile, in a bowl work the egg yolks with the sugar, mix well and then add the cornstarch.

  Once everything is combined set it aside.

• As soon as the milk reaches a boil, remove the lemon zest and pour it slowly, little by little, into the egg mixture, whisking quickly by hand to temper the eggs and prevent them from curdling.

  Return the mixture to the heat over low flame and continue cooking, stirring with a whisk or wooden spoon until it thickens.

  When cooked, place it in a bowl, cover it directly with plastic wrap to prevent that annoying skin from forming on the surface and let it cool completely.

• Whisk the custard to make it soft and smooth again, then whip the very cold cream and gently fold it into the custard using an upward motion.

  Put it into a piping bag with a long, thin tip and transfer it to the refrigerator.

• Pour the water, butter, sugar and a pinch of salt into a saucepan.

  As soon as the water begins to boil, remove from the heat and add the flour all at once, stirring vigorously.

  When the flour has incorporated into the dough, return the pot to the heat and stir the mixture with a wooden spoon until it comes away from the sides and becomes quite firm.

  Remove the mixture from the heat, transfer it to a bowl and let it cool slightly. Add the eggs one at a time, waiting for each egg to be well incorporated before adding the next. You should obtain a smooth and fairly firm dough.

  

• Heat the oil in a high-sided pan. When it has reached the right temperature, if you don’t have a kitchen thermometer, place a toothpick in the center of the pan: if it starts to sizzle the oil is ready. Start frying.

  Fill half a teaspoon with the dough and, using another teaspoon, drop it into the oil. Fry a few tortelli at a time (they will expand while cooking), keeping the heat low so they cook through inside.

  Cook them for about 3 minutes, turning them occasionally, then drain them on paper towels.

  Once frying is finished, toss the tortelli in granulated sugar until they are completely coated.

  

• Use the piping bag to make a small hole in each tortello and fill them with custard—don’t be stingy. Place them on a serving plate and serve.

  They are ideal eaten freshly made but, if you have leftovers, you can store them in the refrigerator for 1 day; take them out a few minutes before serving.