Oven BBQ Chicken

2 1/2 lbs chicken peices
1/4 tsp each salt and pepper
1 tbsp vegetable oil
1 onion finely chopped
3/4 cup ketchup
1/4 cup cider vinegar
1 tbsp each worcestershire sauce and brown sugar
1 tsp dry mustard
dash tobasco sauce

Preheat oven to 450F. Arrange chicken in single layer on a greased 13x9" baking dish and sprinkle with salt and pepper. In large skillet, heat oil over medium-high heat. Add onioin and cook, stirring for 5 minutes until soft and not brown. Stir in remaining ingredients. Bring to a boil stirring constantly. Spoon sauce evenly over chicken. Bake uncovered 20-30 minutes or until not pink. Remove chicken to a warm serving plate and whisk cooking juices to combine them then pour evenly over chicken.