In a large skillet, brown the chicken on each side in oil. Add salt and pepper. Set aside in a square baking dish of about 8 inches.
In the same skillet, brown the onions and garlic cloves. Add more oil if needed. Add salt and pepper. Deglaze with white wine vinegar and pour on the chicken. Cook in oven about 30 minutes (flip the chicken at mid-cooking).
Add chicken stock, tomatoes and honey. Keep cooking about 10 minutes. Adjust seasoning and sprinkle with tarragon.