Variations
Instead of roasted chiles, substitute 1 ½ tablespoons seeded, minced jalapeño for the roasted chiles.
Instead of sour cream, use full fat Greek yogurt instead. Avoid using low fat yogurt or sour cream as it will be runny and make the mayo mixture extra thin.
For the no-cilantro-thank-you-very-much fans, use chopped green onion or finely minced parsley.