Peel 3 onions and cut into slices. Clean and wash the carrots, celery and leek and cut them into large pieces. Wash the herbs, shake dry and tie them together with kitchen string to a bouquet.
Wash the meat, dab dry and rub with salt and pepper. Heat the oil in a roasting pan and fry the meat thoroughly all around. Add onion slices, carrots, celery and leek, fry briefly.
Add peppercorns and tomato paste. Add wine and beef stock and bring to the boil. Cover the roaster. Braise in the preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: level 2) for about 2 1/2 hours.
Meanwhile, put the beans in 250 ml boiling salted water, bring to the boil, cover and cook for about 5 minutes, stirring several times. Peel and finely dice 1 onion. Wash the thyme, shake dry and pluck the leaves from the stalks.
Butter in a small pot, fry the onion and thyme a little. Stir starch and 5 tablespoons of water until smooth. Lift the roast out of the roaster, keep warm. Pour the stock through a sieve and collect.
Keep vegetables warm. Bring the roast stock to the boil, stir in the starch, bring to the boil again, simmer for 1 minute. Season with salt, pepper and sugar. Put the vegetables back into the sauce. Serve roast and vegetables in sauce in a deep dish.
Pour the beans into a sieve, drain. Pour onion and thyme butter over the beans and serve in a bowl.