1 (3-4 lb.) beef tenderloin
1/2 c. chopped onion
1 1/2 tbsp. butter, melted
1 c. dry sherry
3 tbsp. soy sauce
2 tsp. dry mustard
1/8 tsp. salt
1/8 tsp. pepper

Saute onion in butter until tender. Add remaining ingredients (except beef) and mix well. Trim excess fat from tenderloin. Pour marinade over tenderloin in bowl or container large enough for juices to cover as much of meat as possible. Cover and refrigerate 8 hours, turning meat occasionally or spooning marinade over meat. Remove meat from marinade and place in large shallow baking or roasting pan.

Bake, uncovered at 400 degrees for 10 minutes. Reduce heat to 325 degrees. Pour marinade over meat. Bake 35 minutes or until a meat thermometer reaches 140 to 170 degrees. Baste often. Slice tenderloin and serve with juices. Yield: about 10 servings.