For dinner the other day. This idea came from a Chinese/Western cuisine restaurant, typical of the Canadian prairies, that I went to as a child in the 70's.
From the top bun down, we have:
roasted red pepper hummus
leafy spring greens
a fresh pineapple ring
a mushroom based veggie burger topped with cheese and julienned red onions
finally barbecue sauce on the bottom bun
My wife baked the cheese/onion on the burger and the pineapple as well.