Easy baked chicken with rosemary and garlic

1 onion, diced
1/4 C red wine vinegar
1 T olive oil
1 T dijon mustard
1 t rosemary
2 cloves of garlic, sliced thinly
1/2 t salt
1 3- to 4-lb chicken, cut in eighths, skin removed
Preheat oven to 400 F. Spray a 9 by 13-inch baking pan with cooking spray.
Combine all ingredients except the chicken in a small bowl. Place the chicken in the baking pan. Spoon the onion mixture over the top. Bake until the chicken is browned and cooked through (about 45 minutes). Do not turn it.

Six 220-calorie servings.