Put the beef roast, weighing about 1 kg, with rosemary, garlic, carrot and onion for 24 hours. Then roast everything together in the oven for about one and a half hours. Cool roast and spread cold sauce through a fine sieve.
Roast the meat in a clay pot with oil. Add one tomato, one onion and two cloves of garlic. When it is golden brown, add a glass of red wine and simmer. Roast the mushrooms in a frying pan and flambé with cognac.
Cut the roast into slices and mix everything together in the clay pot. Let it simmer again for a short time, so that the different flavors mix.