3/4 cup buttermilk
1/4 cup low-fat mayonnaise
2 tablespoons white wine vinegar
2 tablespoons minced fresh herbs such as chiles, tarragon, parsley, chives, oregano, etc.
1/2 to 1 garlic clove (about 1/2 to 1 teaspoon), minced, or to taste
1/2 to 1 teaspoon onion powder or to taste
Salt and pepper to taste