In a small mixing bowl whisk together the buttermilk, sour cream and mayonnaise until completely combined and smooth. Add the chives, lemon juice, dill, onion powder, garlic powder, parsley, pepper, mustard powder and salt.
Whisk to combine. Cover and refrigerate until ready to serve. The sauce can be made up to 4 days in advance.
Notes
The dressing can be stored refrigerated in an airtight container for up to 4 days.