Heat the butter and oil in a large saute pan or skillet and brown chicken a few pieces at a time.
Transfer browned chicken to an ovenproof baking dish.
To the remaining oil in the pan, add onion, garlic, and bay leaf, and cook gently for 1-2 minutes until onion is transparent.
Add the vinegar and water and stir to loosen any browned bits from the bottom of the skillet; pour the sauce over the chicken, being sure that the onions are distributed evenly around the chicken pieces and lodge the bay leaf at the bottom.
Season with salt and pepper.
Bake for 1 hour and 15 minutes or until chicken is tender; turn chicken pieces once during baking.
Transfer chicken pieces to serving dish.
Remove fat from pan juices (I usually use a paper towel or lettuce leaf placed on the layer of fat for a few seconds) and pour over the chicken.
Garnish with chopped parsley and serve.
Great with rice or noodles.
MY NOTE: I put the chicken in skin side down first, then covered the baking dish with foil for the first 1/2 hour of cooking, then turned the chicken and removed the foil for the remainder of the cooking time.