Creamy Blue Cheese Dressing

2 cups sour cream
1/4 cup mayonnaise
1-4 oz. package blue cheese (3/4 cup crumbled)
1 tbsp. white vinegar
1 tsp. oil
1 tsp. prepared mustard
1 tsp. onion grated
1/2 tsp. salt
sprinkle black pepper
Blend ingredients in a blender until well blended. Cover, chill- 
up to a few days. Serve over tossed greens or with chicken wings. 
Makes about 2 cups.