Knead the flour with water, oil, salt, and Santa Lucia yeast for 5-6 minutes until you get a soft and smooth dough. Divide into 4 balls and roll them out thinly. Line a tartlet mold previously greased with oil.
Meanwhile, prepare the filling. Mix the ricotta with salt, pepper, and grated cheese and fill the tartlets.
Decorate with a slice of tomato, oregano, and bake in a ventilated oven at 180°C (356°F) for 20 minutes.