This is a great recipe to use leftover roast beef.
List of Ingredients
2 c. leftover Roast
2 TB flour
2 TB butter
1 tsp. dry mustard
1\2 c. brown sugar packed
1\2 C. vinegar
1 1\2 c. hot water
1 envelope onion dry soup mix
Brown beef in butter; stir in flour. Combine remaining ingredients; stir into beef mixture and simmer 20 minutes. Serve at once over fluffy rice or cool the sweet-sour mixture and turn into a freezer container and freeze. Reheat at serving time.