In an ovenproof casserole, cook the diced bacon over a low heat. Add the onion, carrots, shallots, and garlic and cook until softened, about 10 minutes. Stir in the beef, bouquet garni, 4 black peppercorns, and the clove. Cook, stirring occasionally, for 10 minutes. Pour in 2 cups of the wine and bring to a boil. Reduce heat, cover and simmer for 45 minutes. Chop the mushrooms. Melt 2 tablespoons of the butter in a frying pan and cook the mushrooms until softened, about 10 minutes, stirring occasionally. Set aside. Strain the red wine sauce and reduce it to about 1 1/2 cups. In a small bowl whisk together the flour with 2 tablespoons of the butter to obtain a paste. Whisk the paste little by little into the boiling sauce, letting the sauce boil between each addition. Stir in the mushrooms. Season with salt. Just before serving, reheat the sauce and whisk in the remaining butter. Do not boil the sauce once the butter has been added. Serve immediately.
