In a medium bowl, whisk together the sour cream, 1/4 cup mayonnaise, 2 tablespoons milk, dried dill, lemon juice, vinegar, garlic powder, onion powder, 1/4 teaspoon salt, and several grinds of pepper. For a thicker dressing, add more mayonnaise. For a thinner dressing, add more milk.

Season to taste, adding more salt if desired. Fold in the chives and dill, if using.

Use as a salad dressing or dip, or try one of the serving suggestions in the blog post above. Store dressing in an airtight container in the refrigerator for up to 5 days.