Sweet and Sour Chicken

6 boneless, skinless chicken breasts
1 teaspoon garlic salt
½ teaspoon black pepper
1 tablespoon vegetable oil
1 egg, beaten
4-6 tablespoons flour
¾ cup sugar
½ cup vinegar
½ cup chicken stock
3 ½ tablespoons ketchup
1 tablespoon soy sauce

Sprinkle chicken with garlic salt and pepper. Refrigerate for at least 1 hour. Preheat oven to 325°F. Heat oil in a shallow skillet over medium-high heat. Put beaten egg in a shallow dish; place flour in a shallow dish. Dip chicken in beaten egg, then in flour. Place chicken in hot oil and brown on both sides. Place chicken in baking dish and set aside.
Prepare sweet and sour sauce by mixing sugar, vinegar, chicken stock, ketchup, and soy sauce in a medium saucepan and heating until sugar is dissolved. Pour over chicken. Bake uncovered for 1 hour. Turn chicken once or twice during baking time. Serve over rice.