2 c. mayonnaise
1/2 c. sour cream
1/4 c. vinegar
4 tsp. lemon juice
1/2 tsp. dry mustard
1/2 tsp. garlic powder
4 oz. blue cheese, crumbled
1/2 tsp. onion powder

Mix first 7 ingredients. Stir in cheese. Cover. Refrigerate at least 2 hours. Makes 3 cups.