1/2 env. dry onion soup mix
2 tbsp. sugar
1/2 c. ketchup
1/4 c. vinegar
1/4 c. salad oil
1 tbsp. prepared mustard
1/2 c. water

In saucepan, bring above ingredients to a boil. Reduce heat and simmer 20 minutes. Then add 1 1/2 pounds beef chuck, cut in 1 inch cubes. Toss to coat and refrigerate overnight.