Soak bread in milk for about 10 min, squeeze well.
Skin and crush garlic clove. Knead minced meat, garlic and white bread into a mass, season with salt and pepper. Beat the egg and knead it into the dough. Form 24 dumplings of the same size from the meat dough with wet hands. Heat the oil and fry the dumplings in it for about 5 minutes until they are evenly brown. Place the dumplings in a greased heatproof dish. Stir the taco sauce with the roast stock, heat. Add the peeled tomatoes, stir and heat briefly. Pour the sauce over the dumplings. Clean the onion, cut into fine rings and sprinkle over the dumplings.
Sprinkle the grated cheese on top. Put the dumplings on the roasting rack in the oven and bake at 180 °C for 10 minutes.