Barbecued Beef Buns

4 c Cooked Beef Strips -- 2 X 1/4"

1 c Ketchup

1/2 c Cider Vinegar

1/2 c Butter Or Regular Margarine

1/4 c Sugar

2 md Onions -- Thinly Sliced

2 sl Lemon

2 tb Worcestershire Sauce

4 ts Prepared Mustard

1 t Salt

1/4 ts Chili Powder

1/4 ts Black Pepper

1/2 c Water

8 Hamburger Buns

Combine all of the ingredients, except the hamburger buns, in a 4-quart Dutch oven. Cook over high heat until the mixture comes to a boil. Reduce the heat to low and simmer for 25 minutes or until the mixture thickens. Remove the lemon slices. Pour into a container, cover and refrigerate. TO SERVE: Warm over medium heat and serve in the hamburger buns.