Clean and chop the onion finely, soak the bread in water and then squeeze it.
In a bowl, mix the mince, onions, bread, egg and spices.
Grate the cheese and add half of it to the mince.
Knead well and form 8 large meatballs.
Make an indentation in the middle of each meatball and place them in an oiled oven dish.
Wash and chop the tomatoes - dice one, slice the other one.
Put the cubes in the meatball indentations and bake in a preheated 392°F (200 °C) oven for 10 min.
Cover with grated cheese, place a slice of tomato on top of the cheese and bake another 10 min.