1 c. sour cream
1/2 c. buttermilk (add 1-1/2 tsp. vinegar to milk to equal 1/2 c. if you can't find real buttermilk)
1 TB. lemon juice
1 large garlic clove, minced
1 TB. dried parsley, or 3 TB. chopped fresh
1/2 tsp. onion powder
3/4 tsp. kosher salt (or to taste)
1/2 tsp. black pepper
1/8-1/4 tsp. dried dill (to taste) or 1 tsp. fresh.

Mix all ingredients and refridgerate for 1 hour before using.  If you want thicker dressing add more sour cream.