Barbecue Steak Strips

2 lbs round steak
2 T oil
2 C tomato sauce
1/3 C water
2 T brown sugar
1 T prepared mustard
1 T Worcestershire sauce
1 medium onion, thinly sliced (optional)

Slice steak into strips 1/8-inch thick and three inches long. Brown the strips in oil and then pour off drippings. Combine tomato sauce, water, brown sugar, mustard, and Worcestershire sauce. Add this mixture and the onion to the beef strips. Stir well. Cover and cook slowly, stirring occasionally for 30 minutes or until moist and tender.