Cut chicken into 8 pieces. Melt 1/2 of the butter in a heavy bottom skillet. Add thyme, bay leaf and the chicken cut up in pieces, skin side down. Season with salt, pepper and garlic.
Sauté the chicken turning the pieces often, for about 10 minutes. Pour off the fat. Add the vinegar stirring to dissolve the particles adhering to the bottom of the skillet.
Add the stock, tomato paste. Boil and simmer for 10 minutes. Add the remaining butter and parsley. Stir to coat chicken pieces. Serve hot.