Peel onions and garlic. Peel or clean and wash carrots and celery. Dice all but 1 onion and 3 garlic cloves. Wash the meat, dab dry and cut the skin 2-3 times all around.
Then tie each slice into shape with kitchen string, season with salt and pepper and turn in flour. Heat the oil in a frying pan and fry the knuckles light brown while turning them. Take them out. Fry the vegetables, onion and garlic cubes in the frying fat.
Add 1/8 l of wine, veal stock, tomatoes with juice, thyme, oregano, bay leaf, salt and pepper. Cover and braise in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 2 hours.
For the Gremolata, wash the parsley and remove the leaves. Finely chop the remaining garlic and parsley and mix with the lemon peel. Cover and put aside. For the risotto, mix saffron and 3 tablespoons of broth.
Finely dice 1 onion and sauté in 2 tablespoons of butter. Add the rice and fry it while stirring until it becomes glassy. Deglaze with 1/8 litre white wine and boil down while stirring. Add stock in portions, stirring frequently.
Add saffron with the last serving of broth to the rice. After about 20 minutes the rice should be ready: soft but with a firm core. Grate the cheese. Stir in 2 tablespoons of butter and season with freshly ground pepper.
Season the braised stock of the finished ossobuco with salt and pepper and sprinkle with a little Gremolata. Serve immediately with the finished risotto. Add the remaining Gremolata extra.