For the puree, peel and wash the potatoes and cook them in boiling salted water for about 20 minutes. Peel ginger, grate half of it finely and cut the rest of the ginger into thin slices. Peel onion and cut into small cubes.
Heat 1 tablespoon butter, add onion and sauté until translucent. Add the beans, pour on the stock, bring to the boil and cook in a closed saucepan for about 7 minutes. Season with salt and pepper. Wash the meat, dab dry and season with salt and pepper.
Heat the oil in a pan. Add ginger and fry for approx. 1 minute while turning. Remove and place on kitchen paper to drain. Fry meat in hot fat on each side for approx. 3 minutes.
Remove and keep warm. Mash the potatoes, grated ginger and yoghurt into puree. Season to taste with salt and nutmeg. Drain the beans. Arrange meat, beans and puree on plates. Sprinkle with deep-fried ginger slices.