Before we start cooking, remove the kombu pieces from the water. We'll use this soon.
Put a frying pan or wok on a medium heat. Then place in some oil. Once its hot, drop in the meat. Add the onions as well. Stir-fry both around until most of the pink in the meat is gone.
Then add in the spicy marinade. Stir-fry everything for 30 seconds - so the sauce cooks in the heat too. Then, add in the Kombu water. Place the heat on a high and wait until the wok starts to boil again. Then add-in the king oyster mushrooms as well as the enoki mushrooms.
Then we have to simply wait. Let the wok boil away and reduce for 20-30 minutes (depends on your heat of your stovetop). Stir the wok from time-to-time. Turn off the heat when the broth reduce to almost nothing (reference video).
Plate and serve with hot rice!