Blue Cheese Burgers with Balsamic Caramelized Purple Onion

Put butter in a skillet over medium heat. Get the onions going by slicing them thinly into rings and then again once across the rings to make half circles. Put in a skillet with the butter and toss around. Sprinkle a little salt over them. Cover with a lid and let the onions cook down until they are reduced in size by half. Stir them occasionally. Once they have cooked down (add more butter if necessary), add the brown sugar and balsamic vinegar. Basically, you are caramelizing the onions and then making a balsamic reduction.

Meanwhile, cook your hamburger patties and toast the buns.

To assemble, spread mayo on the buns and put on a patty, a spoonful of the onions and as much blue cheese as you can pile on and then the bun. You know how to do that!