Peel and finely chop the onion and 1 clove of garlic. Heat the oil in a pot. Sauté onion and garlic in it. Deglaze with pizza sauce and heat while stirring. Season to taste with salt, pepper and sugar
Halve 2 cloves of garlic. Rub slices of bread with garlic. Heat butter in portions in a large pan. Roast the slices of bread in it in portions and take them out. Halve the slices of bread
Grease 2 casseroles (approx. 17 x 17 cm, 4 cm high) or a large mould. Layer tomato sauce, bread and ham slices in equal parts. Grate the cheese and sprinkle half of it over each. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-15 minutes