Blanch the bacon. Add to a pan of boiling water, simmer for about 5 minutes and rinse in cold water. Dry with paper towels and cut into 1 inch long strips. Place the strips into a large pan and fry them until almost crispy. Remove the bacon strips from the pan and leave to one side. Add your chicken (skin side down) and onions to the pan and brown the chicken well, on all sides (this will take about 10 minutes). Remove any excess fat from the pan and add the sliced garlic, salt and pepper about 2-3 minutes from the end of browning. Return the bacon to the pan and add the chicken stock, wine, and herbs. Cover and simmer for 20-25 minutes, or until chicken is tender and thoroughly cooked. Remove the bay leaves, thyme and parsley from the pan and throw away. With a slotted spoon remove and drain the chicken and onions and keep warm. Add your mushrooms to the liquid in the pan and boil quickly to reduce the liquid. You are looking to reduce the liquid by about 75% until it becomes thick and sauce-like. Once your reduction is complete, reduce the heat and stir in the butter. Return the chicken and onions to the pan ensuring they are thoroughly reheated and fully coated with the sauce.
Garnish with parsley and serve with a selection of vegetables.