Heat clarified butter in an ovenproof saucepan. Season beef and brown well on all sides in the hot clarified butter.
Add onion to meat, cook until golden brown. Add vinegar and cook completely. Add soup and enough water until the meat is about half in the liquid. Cover and cook in the stove heated to 200 °C for 2 to 3 hours. Braise.
Remove the meat and keep it covered and warm.
Boil the stock, add the cream and continue cooking the sauce until it becomes creamy. Strain and season.
Cut the meat into slices and serve with the sauce.
Mass: 4
By the way: Did you know that clarified butter is obtained by extracting water, milk protein and lactose from butter?