Mix the pork in a large bowl with the scallions, cabbage, ginger, garlic, sesame oil, soy sauce, red chili flakes, salt, and pepper. Set aside in the fridge until ready to use.

Poke a hole about the size of a pencil in the center of the wonton wrappers to allow some of the liquid from the filling to drip into the mushroom itself.

Bring a shallow pot of water to a boil and boil the wonton wrappers for about 15 seconds, just enough to slightly soften. drain and spread them on a plate lined with paper towels.

Scrape out the insides of the mushroom caps, scraping a little extra so you can fill them with lots of filling.

Preheat the oven to 350.

Put each wonton wrapper into a mushroom cap, folding the edges over itself to fit snugly. Spoon a bunch of the pork filling into the wonton wrapper and press it down to really fill it.

Line the mushrooms on a rack or just on a baking sheet and bake for 15-17 minutes until the pork is cooked through. Serve.