This is the best I have found, very tasty, I have also used it for tarter sauce with fried fish. This recipe come from Baja California Home of the fish taco. Hope you enjoy it as much as we do. CF:)

Baja Fish Taco Sauce
Ingredients:
• 6 ounces mayonnaise
• 6 ounces sour cream
• 3/4 cup cilantro leaves
• 4 Chipotle chiles in adobo sauce.
• 1 avocado, pitted and pulp extracted.
• 2 tablespoons fresh lime juice
Instructions:
• In a food processor, blend cilantro and chipotle
• Add remaining ingredients and blend
• Keep refrigerated until serving

Sounds like a very interesting twist to tarter sauce. Thank you.