- 2 pounds bone-in chicken breast halves
- 1 large onion, sliced
- 2/3 cup ketchup
- 1/3 cup vinegar
- 1/4 cup butter
- 1 clove garlic, minced
- 1 teaspoon dried rosemary
- 1 teaspoon salt, or to taste
- 1/2 teaspoon dry mustard
- Preheat oven to 375 degrees F (190 degrees C).
- Place chicken breasts in a 9×13 inch baking dish. Put several slices of onion on top.
- In a medium saucepan over medium heat, stir in ketchup, vinegar, butter, garlic, rosemary, salt, and mustard. Bring to a boil, then pour sauce over chicken.
- Bake in a preheated oven for 30 minutes. Turn chicken breasts over, and continue baking until done, about 20 to 30 minutes.