1/4 c. finely chopped onion
1 clove garlic, minced
2 T. vegetable oil
3/4 c. ketchup
1 tsp. grated lemon peel
1 T. lemon juice
1 T. Worcestershire sauce
2 tsp. sugar
1 tsp. dry mustard
1/2 tsp. salt
1/4 tsp. pepper
1/4 tsp. Tabasco sauce
4 lbs. chicken pieces, skin on

Cook onion and garlic in oil until tender. Stir in ketchup, lemon peel, lemon juice, Worcestershire, sugar, dry mustard, salt, pepper, and Tabasco. Simmer over low heat, covered, about 30 minutes, stirring occasionally. Remove from heat. Season chicken pieces with salt and pepper. Place bone side down over medium hot grill for 25 minutes. Turn skin side down; grill 20 minutes more. Brush with barbecue sauce and continue grilling until done, 10 to 15 more minutes, turning frequently and basting with sauce.

I sometimes cook the chicken, covered, in a 350-degree oven for the first 30 minutes, then transfer to the grill to finish cooking. This helps the chicken to cook thoroughly without getting too dark on the outside.