Start by bringing a large pot of salted water to a boil. Carefully add the halved red potatoes and cook for about 15–20 minutes, or until fork-tender. Drain and let cool.

While the potatoes cool, prepare the dressing by blending avocado, mayonnaise, buttermilk, parsley, chives, lemon juice, tarragon, anchovy fillets, and shallots until smooth.

In a large mixing bowl, combine cooled potatoes, trimmed snap peas, and chopped celery. Gently fold to mix without breaking potatoes.

Pour the Green Goddess dressing over the potato mixture. Carefully toss to coat without smashing the potatoes.

Cover salad with plastic wrap and refrigerate for 30 minutes to 1 hour for enhanced flavors.