1 3-lb. chicken, cut into pieces and skinned
1 14.5 oz. can tomato sauce
1 medium onion, chopped
1/4 cup apple cider vinegar
3 Tablespoons brown sugar
1-1/2 Tablespoons Worcestershire sauce
1 Tablespoon tomato paste
1/2 teaspoon salt, plus more to taste
1/2 teaspoon sweet basil, dried
1/2 teaspoon dried thyme
1/4 teaspoon freshly ground black pepper, plus more to taste
Hot pepper flakes (optional)