Place chicken, wine, vegetables, garlic, half of the bacon and bouquet garni in a large bowl. Cover and marinate in refrigerator overnight. Remove chicken from marinade, being sure to reserve the marinade for later use. Pat dry the chicken with a towel, and in a casserole dish or heavy bottomed pot, heat oil and sear chicken until golden brown. Next add bacon from marinade to chicken and cook until just brown. Discard the bouquet garni and vegetables from the marinade and strain. Add the cognac to the chicken and flambe, and then add the marinade. Simmer until the chicken is tender, about 45 minutes to 1 hour. With a ladle or spoon, remove all excess fat from the sauce. Next thicken the sauce. If using blood, do not boil, but simmer gently. If using cornstarch, first mix it with water and create a slurry, add it to the sauce and bring to a boil. In a separate pan, saute mushrooms and onions in bacon or duck fat until brown. Julienne remaining half of the bacon and sear until brown. Make croutons: toast 8 slices of baguette, rub with garlic and drizzle with olive oil. To serve, heat chicken and vegetables in sauce. Garnish with mushrooms, onions, bacon, and garlic.