Wash the meat, cut in half at the joint and place in a large pot. Peel and halve 1 onion. Clean and wash the soup greens. Peel carrots and celery. Cut everything into large pieces. Put onion, soup green, bay leaf and peppercorns in the pot. Add about 3 litres of water so that the meat is covered. Salt, bring everything to the boil and simmer gently over a low heat for about 1 1/2 hours. Skim off any foam that develops
Lift the legs out of the broth, drain well. Pour the stock through a sieve and use it for other purposes. Season the legs with salt and paprika all around and spread them in the oiled fat pan of the oven. Cook in the preheated oven (electric cooker: 200 °C/ circulating air: 175 °C/ gas: see manufacturer) for approx. 1 hour
In the meantime peel the remaining onions and cut them into slices. Peel and roughly dice the carrots. Heat oil in a pot and fry onion and carrots for about 4 minutes. Deglaze with red wine, bring to the boil and simmer for about 4 minutes. Add tomatoes, chop coarsely with a spatula, bring to the boil and simmer gently for about 10 minutes. Season to taste with salt, pepper and sugar
For the Gremolata, wash the lemons hot, grate them dry and thinly grate the rind. Peel garlic and chop finely. Wash parsley and basil, shake dry, pluck leaves from stalks and chop finely. Mix the prepared ingredients
Spread the prepared sauce over and around the legs. Cook in the oven for another 15 minutes. Arrange the legs and spread Gremolata on top