1 (8 oz.) carton commercial sour cream
2 to 3 tsp. prepared horseradish
1 tsp. Worcestershire sauce
1/2 tsp. onion salt
Dash of ground red pepper

Combine all ingredients, stir well. Cover and chill 1 to 2 hours. Serve with rolls and beef tenderloin.

This sauce is especially good if you are serving cold tenderloin. I usually slice the meat, stuff it in a roll and let the company help themselves to the sauce, which is put in a pretty gravy boat with a nice serving spoon.