Horseradish Sauce

I made this for dinner group the other night and loved it, I will definitional use it again! I put it on roast beef sandwiches, with provolone cheese, sauteed green peppers, and caramelized onions, then broiled them.

• 2 tablespoons prepared horseradish
• 1 tablespoon cider vinegar
• 1 teaspoon dry mustard
• 3 tablespoons reduced-fat mayonnaise
• 1/8 teaspoon ground red pepper
• 1/2 cup nonfat sour cream

As suggested by one of the reviews I read I left out the vinegar and did about half the sour cream. Next time I would double the horseradish, but I love that really strong flavor. 2 tablespoons was pretty mild in my opinion.