Put the flour in the shape of a volcano and make a hole in the center, where you pour the yeast dissolved in warm water.
Add the oil, a little water and salt.
It is kneaded well until we see that it does not stick to the hands.
Let it rest covered with a cloth.
Cook the tomato and pass through a sieve.
Roll out the dough with a rolling pin, place it in the chosen mold and on it, the chopped onion, the grated cheese, the oil, the mozzarella pieces and the oregano.