1 1/4 c. milk
1 c. buttermilk
2 1/4 c. mayonnaise
1/4 c. cider vinegar
1/2 c. grated Parmesan cheese
1/4 tsp. white pepper
2 tsp. garlic powder
1 1/2 c. sour cream

In a large mixing bowl, combine all ingredients except sour cream. Mix well with a wire whisk. Fold in sour cream leaving lumps intact. Refrigerate in tightly closed container.