Peel and wash the potatoes and cook them in salted water for about 20 minutes. Drain potatoes and let them cool down a little
Cook the beans in boiling salted water for about 12 minutes. Peel and finely dice the onion
Heat the oil in a coated pan. Fry the steak for about 2 minutes on each side. Add the potatoes to the pan and fry until golden brown all around. Sprinkle with cheese. Melt the cheese. Season steak with salt and pepper. Remove everything from the pan and keep warm
Sauté onion in the frying fat. Stir in 100 ml water and stock, bring to the boil and thicken. Add peppercorns. Flavour sauce. Drain the beans and sprinkle with parsley. Serve everything