Wipe the portobello mushrooms with a clean damp cloth. If desired, you can use a metal spoon to scale off the gills on the underside of the mushroom, I usually don’t. In a lidded container, mix all of the marinade ingredients, and then add the mushrooms. Put the lid on the container, and shake. Marinate for about a half hour or even overnight, flipping the container so both caps get marinated.
To make the slaw, simply mix all the ingredients together in a bowl.
Grill the mushroom caps: Preheat your grill, and grill the caps for about 5 minutes on both sides. I like to drizzle or brush the caps with the marinade a couple of times.
To serve, toast burger buns if using, then add the porto-burgers and top with slaw and extra cilantro, if desired. You could also add healthy vegan mayo or mashed avocado, onion slices, or whatever toppings you like!
