Preheat oven to 300℉.
Arrange ribs in a 3 to 4 quart roasting pan with a cover Scatter separated onion rings over and around ribs.
In a medium bowl, combine ketchup, sugar, water, soy sauce, vinegar and Worcestershire sauce. Pour mixture over the ribs and onions.
Cover the ribs. Bake untouched for 3 hours.
