Carve tomatoes crosswise, blanch with boiling water, rinse cold and peel the skin. Cut the tomatoes into small pieces. Peel carrots, clean celery. Wash both and cut into small cubes.
Peel and finely dice the onions and two garlic cloves. Rinse slices of meat and pat dry. Season with salt and pepper and turn in flour. Tap off excess flour.
Preheat oven (electric cooker: 200 °C/recirculating air: 175 °C/gas: see manufacturer). Heat oil in a large roaster. Fry the slices of meat in it until they are brown and remove from the roaster.
Add the diced vegetables, onions and diced garlic to the cooking fat and sauté briefly.
Meanwhile, wash the thyme and oregano, shake dry and chop. Add the bay leaf and slices of meat to the roaster. Add wine and 1⁄4 l water and bring to the boil. Add tomato pieces. Cover and braise in the oven for about 2 hours until the meat comes off the bone.
Meanwhile, for the Gremolata, wash the lemons hot, dab dry and finely grate the rind. Wash parsley, shake dry and cut the leaves finely. Peel the rest of the garlic and chop finely. Mix all ingredients.
Season ossobuco with salt and pepper. Serve with gremolata. Serve with ciabatta or saffron risotto.