1. Place the meat in a pot of cold salted water with the peeled onion and cloves. Let it boil for 15 minutes, skimming regularly, then let it simmer.
2. Clean the leeks and cut them into sections along with the peeled carrots. Add them to the pot along with the bouquet garni, salt, and pepper. Bring to a boil, skim, then let it simmer for 1 hour and 15 minutes.
3. Clean the mushrooms. Sauté the peeled pearl onions in 30g of butter. Add the quartered mushrooms, season with salt, and let them cook on low heat until the water evaporates.
4. Meanwhile, heat 30g of butter, add the flour, mix, and let it cook for 2 minutes on low heat. Let the resulting roux cool down.
5. Place the meat and vegetables in a dish and keep warm. Strain the broth, pour it over the roux, and whisk until you obtain a very smooth sauce. Let it cook for 5 minutes on low heat. Beat the cream with the egg yolks, gradually add it to the sauce while whisking on low heat. Pour the sauce over the dish and serve immediately.
6. Serve with rice.