Preheat oven to 350. In a medium bowl,combine egg, milk, breadcrumbs,salt, pepper,sage and onion. Stir in ground beef. Shape into 1-inch balls. Arrange on a rack in broiler pan. Bake 15-20 minutes. Drain and discard drippings.
Prepare Sweet and Sour Sauce:
Drain pineapple; reserve juice ina a small saucepan;set aside. Cut pineapple into 3/4 inch pieces;set aside. Stir cornstarch into reserved pineapple juice until dissolved. Stir in soy sauce, broth,vinegar and honey. Cook and stir over medium-low heat until thickened and translucent. Stir in pineapple chunks and green pepper squares. Cook one minute longer.
Pour sauce over meatballs. Serve warm. Makes about 55 meatballs.(small)