Meanwhile, peel the onion, cut into cubes and fry in oil. Clean the mushrooms, cut them into slices and fry them too. Peel, grate and fry the carrots. Season with salt and pepper. Deglaze with about 150 ml of white wine. Let simmer for 2 minutes. Mix the sour cream with the cream and pour over the mushrooms and carrots. Mix well and season to taste.