1 15-ounce jar mayonnaise (about 1½ cups)
¼ cup distilled white vinegar
1 tablespoon apple juice
Juice of ½ lemon
2 teaspoons freshly ground black pepper
2 teaspoons prepared horseradish
¼ teaspoon kosher salt
¼ teaspoon cayenne pepper
Combine all the ingredients in a bowl and whisk well to combine, then serve over barbecue chicken.
Store any remaining sauce in an airtight container, refrigerated. Stir before serving.