Typically these are filled with mozzarella and fresh tomato. Once you have mastered this, move on to filling them with many other items such as salumi or anchovies or artichokes.
1 package active dry yeast
Pinch of sugar
3 ½ tablespoons extra virgin olive oil
sea salt and freshly grounded black pepper
3 cups flour, (try to find 00 flour if you can)
½ pound plum tomatoes peeled and coarsely chopped
4 ounces fresh mozzarella, cut into 16 pieces of roughly equal size
1 ½ to 2 cups vegetable oil- for deep frying.
In a large bowl, dissolve the yeast and sugar in ¼ cup warm water. Let it proof until an active foam starts to form on top. Add 3 tablespoons of the olive oil, ½ teaspoon salt, several grinds of fresh pepper, and 1 cup warm water.
Add 2 1/2 cups of the flour, a half cup at a time, until the dough forms. Turn the dough out onto a lightly floured work surface adding a little flour as you knead it. You don’t want the dough to be sticky, but you don’t want it dry. Shape the dough into a ball and let it sit in a large oiled bowl. Leave for about an hour until it is doubled in size.
Cut the tomatoes in half and remove the seeds. Coarsely chop the tomatoes. It’s even better if you let them drain in a colander for about 30 minutes so they are not wet.
After the dough has risen, cut it into four pieces. Then cut each dough into four pieces.
Take the sixteen pieces, one at a time, and roll it out into about a four inch round. Place a spoonful of tomato and a piece of mozzarella on one side. Fold over the other side and seal.
Heat the vegetable oil to about 370 degrees. Fry them a few at a time. Don’t crowd the pan. When the dough is golden brown, remove them to drain. Let the inside cool a little but serve them warm.