Pat chicken pieces dry and season with salt and pepper. Heat butter and oil in large skillet and brown chicken over medium heat for 5 minutes. Add onion, ginger and sherry. Stir and add remaining ingredients except cornstarch and strawberries. Bring to a boil, reduce heat and simmer for 25 minutes Remove chicken pieces to serving dish. Dissolve cornstarch in 3 tablespoons of water. Stir into the sauce and cook until the sauce thickens. Add the strawberries. Gently toss and spoon over the chicken.