Remove the crusts from toast and soak in cold water. Meanwhile peel onions and garlic. Cut onions into fine cubes. Press 1 garlic clove through a garlic press. Squeeze the toast.
Knead minced meat, toast, egg, 1 onion and garlic. Wash thyme, dab dry and pluck leaves from the stalks, except some for garnishing. Chop the thyme finely and knead half of it into the chopped mass.
Season with salt and pepper. Cover the mince mixture and chill. In the meantime, carve tomatoes crosswise, boil water over them and peel off skin. Cut the tomatoes into quarters. Cut out the stalk and seeds.
Dice the flesh. Heat oil in a pot. Press 2 cloves of garlic through a garlic press. Fry the rest of the onion cubes and garlic in it until transparent. Add the tomatoes. Season with salt, pepper, cinnamon and remaining thyme and simmer for 5 minutes at low heat.
In the meantime, shape the minced meat mixture into 20 walnut-sized balls and add to the sauce. Let the meatballs simmer in the sauce for 15-20 minutes. Garnish with thyme. Serve with flatbread with sesame seeds.