In a food processor add the skinned and pitted avocado, sour cream, mayonnaise, lemon juice, parsley, garlic, onion powder, white vinegar, salt, and pepper.
1 large ripe avocado, 1/4 cup sour cream, 3 tablespoons mayonnaise, 2 teaspoons lemon juice, 1 garlic clove, 1 teaspoon white vinegar, 1 bunch fresh parsley, 1/4 teaspoon onion powder, salt and pepper to taste