01 - Whisk mayonnaise and sour cream in a medium bowl until completely smooth and well combined.
02 - Add minced jalapeños, jalapeño brine, garlic, cumin, onion powder, salt, and black pepper. Mix thoroughly to distribute spices evenly.
03 - Pour in fresh lime juice and fold in chopped cilantro. Stir until ingredients are uniformly blended throughout the sauce.
04 - Cover bowl tightly and refrigerate for minimum 1 hour to allow flavors to develop and meld together.
05 - Remove from refrigerator, give sauce a final stir, and serve chilled as a dipping sauce or condiment.