Marinate the chicken in a mix of the white wine, garlic cloves, bouquet garni, olive oil, salt and pepper for 1 or 2 hours in the refrigerator.
Preheat the oven to 350ºF.
Add the chopped onion to the bottom of a Dutch oven, or other heavy casserole with a lid. Add the chicken, and then pour in the marinade including the bouquet garni and garlic cloves.
Cover and roast for 1 hour and 30 minutes. Discard the bouquet garni before serving.
Serve with toasted slices of baguette for spreading on the roasted garlic which will have a smooth silky texture.