Jack in the Box mayo-onion sauce
A recreation of this iconic sauce from Jack in the Box that was used on the Sourdough Jack, Chicken Supreme, Ultimate Cheeseburger (pre-2002) and Hot Ham and Cheese.
jack in the box, mayo, onion, sauce
or corn syrup
dry mustard powder
or yellow mustard
Mix the vinegar, sugar, onion and mustard until the sugar dissolves
Add a pinch of xanthan gum while mixing and allow to sit until it thickens slightly
Add mayonnaise. You can use it immediately, but it will get better as it sits. Allow at least an hour for the best flavor.
This should make enough sauce for about four burgers or sandwiches.