Break the sourdough starter into pieces and dissolve it in the warm milk. Gradually add the olive oil and sugar, stirring continuously.

Add the flour mixed with salt and knead the dough until smooth and elastic. Cover with plastic wrap and let rise until doubled in size.

After about three hours, roll out the dough and cut out small rounds. Let them rise for another hour.

Preheat the oven to 375°F (190°C). Top the mini pizzas with tomato sauce, olive oil, and mozzarella. Bake for about 20 minutes.