Ruth's beef tenderloin
1/4 lb. butter
1/4-1/2 c. ketchup
1/2 tsp. dry mustard

Cut off and trim white muscle and fat. Combine melted butter, ketchup and mustard. Place tenderloin on broiler pan. Baste tenderloin with butter mixture. Broil on the first side. Turn and baste tenderloin often with butter mixture, while baking at 350 degrees for 35 minutes (or more). Use meat thermometer. Should register 140 degrees for rare.