01 - Combine mayonnaise and sour cream in a medium bowl. Whisk until completely smooth and uniform in texture.
02 - Stir in minced jalapeños, jalapeño brine, garlic, cumin, onion powder, salt, and black pepper. Mix thoroughly to distribute spices evenly.
03 - Add fresh lime juice and chopped cilantro. Fold ingredients together until well incorporated.
04 - Cover bowl tightly and refrigerate for at least 1 hour. This resting period allows flavors to develop and meld properly.
05 - Remove from refrigerator and stir well before serving. Sauce should be served chilled.