Carmelized Onion Burgers

Ingredients

2 small (or one very large) onions
3 cloves garlic
half a lemon
apple cider vinegar
baby arugula
mayonnaise
hamburger patties
whole wheat kaiser rolls as hamburger buns
cheese slices - muenster, havarti, provolone, or smoked gouda

Instructions

Dice onions, mince garlic, juice the lemon.
Whip together with a spoon to make aioli: mayonnaise, juice from the lemon, and the minced garlic. Add mayonnaise as you go until you get the desired consistency.
Grill the diced onions and hamburger patties in oil. As onions near carmlization, spread apple cider vinegar on them for the last minute or so.
After flipping patties, add cheese slices.
Toast the buns on the grill as well.

Serve: buns, patties, onions, aioli, and the arugula on its own.

Build: spread aioli on the bun, place a patty with cheese on, spread some carmelized onions on it, and heap arugula on top before mashing it down with the top bun.