Sweet & Sour Meatballs

Sweet & Sour Meatballs made by my husband, so delicious. This can be made in advance and kept warm in a crockpot.
SWEET-AND-SOUR MEATBALLS
MEATBALLS:
1 pound ground hamburger
1/4 cup milk
1 teaspoon salt
1 egg
1/2 cup dry breadcrumbs
2 tablespoon finely chopped onion
1/2 teaspoon Worcestershire sauce
Mix ingredients; shape into twenty 1 1/2-inch balls. Cook over medium heat, turning occasionally, until brown, about 20 minutes. Remove and drain fat from skillet.
SAUCE:
1/2 cup packed brown sugar
1 can (13 1/4 oz.) pineapple chunks
1 tablespoon cornstarch
1/3 cup vinegar
1 tablespoon soy sauce
1 small green pepper, coarsely chopped
Mix brown sugar and cornstarch in skillet. Stir in pineapple (with syrup), vinegar and soy sauce. Heat to boiling, stirring constantly; reduce heat. Add meatballs. Cover, simmer, stirring occasionally, 10 minutes. Stir in green pepper. Cover; simmer until crisp-tender, about 5 minutes.