Western Chuck Steak

Recipe:

? cup Ketchup
? cup Soy Sauce
? cup Cider Vinegar
1 small Onion, chopped
3 to 4 lb. Beef Chuck Blade Steak (? to 1 inch thick)

1. Combine first 4 ingredients in saucepan; bring to boil.
2. Simmer 5 minutes; cool.
3. Pour into plastic bag with meat.
4. Refrigerate 8 to 10 hours, or overnight.
5. Broil 8 to 10 minutes on each side (for rare or medium doneness).
6. To serve, cut across grain into thin slices.