In a small bowl, combine ¼ cup mayonnaise, ¼ cup sour cream, 2 tablespoons minced cilantro, 2 teaspoons garlic powder, and 1 tablespoon lime juice.
Add 3 chipotle peppers in adobo sauce, chopped, plus 2 tablespoons adobo sauce and ½ teaspoon ground cumin (if using).
Season to taste with salt and pepper.
If desired, add more chipotle pepper for a spicier sauce.
Set aside.
