Snip the outer edge of the shank slices with scissors or a sharp knife to prevent them from curling upon cooking. Sprinkle them with salt and pepper and coat with flour. Peel and finely chop the onions. Peel the carrot and cut it into small pieces. Finely chop the peeled garlic cloves, the celery and the thyme. Cut a cross in the tomato bases and place in hot water for a few moments. Skin them, remove the seeds and cut the flesh into cubes.
Heat the butter with the olive oil and brown the meat briefly. Add the onions, carrot, garlic, celery, thyme and lemon rind and braise for a few minutes. Add the wine and veal stock and braise gently, with some bayleaf, with the lid on the pan for 1½ houres. The meat should not fall off the bone. Add a few tablespoons of veal stock if the sauce appears too thick. If the sauce is too thin, thicken it with 15 gr. of butter mixed with ½ tbsp. of flour. The braising juices can be puréed with a hand mixer if required. Chop the sprigs of rosemary or marjoram and sprinkle these over the dish.
Serve the ossobuco with a risotto with grated parmesan cheese or pecorino.
* Add a special touch to the dish by adding so-called gremolata at the last moment. Gremolata is a mixture of freshly chopped parsley, grated lemon rind, freshly chopped garlic and ground anchovy fillets or sardines.
* Add 2 tbsp. of fresh orange juice to the sauce for a fresher taste.