Challah bread buns aren't easy to find but I saw them and had to use em.

I took my my diced onions dumped some Belching Beaver Peanut Butter Stout in the mix and reduced my onions until fully caramelized, then topped 3 smash patties with the onions, and finished with a creamy hot honey mustard aioli. Not the prettiest thing but it was damn good.