Wash and clean the beans and possibly halve them depending on their length. Peel, wash and halve the potatoes and cook in boiling salted water for about 20 minutes. Cover the beans and cook in little boiling salted water for about 15 minutes.
Roast sesame seeds in a pan without fat while turning. Wash the meat, dab dry and season with salt. Heat the oil in a pan and fry the meat thoroughly all around. Season with pepper. Add stock and wine, bring to the boil and cook the meat in the closed pan for another 5 minutes.
Peel and finely chop the onion. Pour the beans onto a sieve and let them drain. Heat the fat in the bean pan and fry the diced onion in it. Add the beans, toss them and season to taste with salt, pepper and nutmeg.
Remove the meat from the pan, wrap in aluminium foil and leave to rest. Warm the milk. Drain the potatoes, add the milk and mash the potatoes with a potato masher to form a puree. Stir in crème fraîche and sesame seeds, season with salt and pepper.
Cut the meat into pieces. Arrange puree, beans, meat and gravy on plates.