01 - Combine mayonnaise, sour cream, lemon juice, vinegar, parsley, chives, tarragon, basil, anchovy fillets, garlic, salt, and pepper in a blender or food processor. Blend until completely smooth and creamy. Taste and adjust seasoning as desired. Transfer to an airtight container and refrigerate until serving.
02 - Place mixed salad greens, cucumber slices, radishes, and snap peas in a large salad bowl. Drizzle with 1/2 cup of the prepared Green Goddess dressing. Gently toss to ensure all vegetables are evenly coated.
03 - Arrange sliced avocado over the dressed salad. Sprinkle with fresh parsley, dill, or chives for garnish. Serve immediately on chilled plates with remaining dressing on the side for additional portioning.