Sauté the chopped onion with the extra virgin olive oil, until golden and soft.

Add the ground beef and pork and mix well breaking up all the lumps with a wooden spoon. Brown the meat on a medium to high flame, then add the white wine and let the alcohol evaporate.

Season with salt and pepper to taste and cook for a few minutes, until all the liquid has evaporated. Keep it aside to cool down.

When cool, add the beaten egg, the grated Pecorino Romano and the pinch of nutmeg. Mix well and keep aside.

To make the dough, dissolve the yeast in the lukewarm milk, add the sugar, mix well and keep it aside until frothy.

Put all the remaining ingredients in the bowl of an electric mixer fitted with a hook attachment.

When the yeast mixture is frothy, add it to the bowl. Knead well for a few minutes until you get a smooth and pliable dough (you may need to add a couple of tbsp of milk at this stage, depending on how your flour absorbs the liquid. The final dough has to resemble pizza/bread dough in consistency).

When ready, make it into a ball, dust it with flour and keep it in a warm place until it doubles in size.

Take the risen dough and divide it into 10 smaller balls.

Flatten them with a rolling pin into 0.5 cm – 0.2 inch thick circles.

Put a heaped tablespoon of filling in the middle of each circle and top it with some chopped mozzarella.

Fold the dough in half and seal it well by crimping the edges closed with your fingers.

Deep fry in hot vegetable oil until golden brown on both sides. Put them on a plate covered with kitchen paper to drain the excess oil and serve warm.