01 - Whisk mayonnaise and sour cream together in a medium bowl until completely smooth and uniform in texture.
02 - Add minced jalapeños, jalapeño brine, garlic, cumin, onion powder, salt, and black pepper to the bowl. Mix thoroughly to distribute spices evenly.
03 - Pour in fresh lime juice and sprinkle chopped cilantro over the mixture. Stir well to integrate all ingredients.
04 - Cover the bowl tightly and refrigerate for a minimum of 1 hour, allowing seasonings to fully develop and blend together.
05 - Remove from refrigerator and give the sauce a final stir before serving. Serve chilled alongside tortilla chips, over tacos, or with grilled meats.