Make a well with the flour, create a hole in the center, and add the melted lard, San Gennaro yeast, salt, and a bit of milk. Knead, adding enough milk to get a smooth and fairly firm dough.
Shape the dough into a ball and let it rest in a bowl covered with a kitchen towel for 30 minutes.
Roll out the dough into a thin sheet (about 3 mm thick) and cut it into diamond shapes about 6–7 cm long.
In a wide enough frying pan, heat vegetable oil (or lard) and fry the diamond shapes for 1 minute per side, until lightly golden. The bubbles that form while frying are a sign that the dough has risen perfectly.
Place the fried crescentine on a tray lined with paper towels and serve them hot, accompanied by cured meats, cheeses, pickles, and homemade preserves.
If you have leftovers, they also go very well with Nutella or jams.