n a large bowl, mix together the shredded mini cabbage, carrot, red onion and a handful of coriander - set aside. Reserve some red onion slices and coriander.
In a small bowl mix together the mayo, Sriracha, honey, soy sauce, sesame oil and toasted sesame seeds -set aside.
In a griddle pan over a high heat or on the BBQ - drizzle a little sesame oil over the mushrooms and grill bottom side down. Once browned, flip them and spread a teaspoon of oyster sauce on each mushroom. Continue grilling until the mushrooms are juicy and cooked through.
While the mushrooms are cooking on a high heat, fry off the burger patties on a high heat for 3-4 minutes on each side with a drizzle of sesame oil.
Take the mushrooms and the patties off the heat and cover with tinfoil to rest for 5 minutes.
Smear some mayo inside of the burger buns and grill on a low heat until warmed through and a little charred.
Fold the dressing through the slaw.
To assemble the burger, spread a layer of sriracha on the bottom bun.Top with slaw, burger patty, cucumber, mushroom, red onion slices and coriander then top with the top bun. Insert a skewer to keep the burger in place.