Preheat oven to 350°. In a large ovenproof skillet, heat oil over medium-high heat. Brown chicken on both sides. Remove from pan. In same pan, heat butter over medium-high heat. Add onion; cook and stir until tender, about 1 minute.
Stir in barbecue sauce, brown sugar, vinegar and honey. Bring to a boil. Reduce heat; simmer, uncovered, until thickened, 4-6 minutes. Return chicken to pan. Bake until a thermometer reads 165°, 12-15 minutes. Stir in strawberries.
Nutrition Facts 1 chicken breast half with 1/3 cup sauce: 495 calories, 17g fat (5g saturated fat), 109mg cholesterol, 829mg sodium, 49g carbohydrate (42g sugars, 2g fibre), 35g protein.