Start by gathering all your ingredients. Clean the mushrooms gently with a damp cloth to remove any dirt. Slice the king oyster mushrooms into strips. For shiitake, remove the stems, then slice them.
In a large skillet, heat the vegetable oil over medium heat. Add the sliced king oyster mushrooms first. Cook for about 3 minutes until they soften. Next, add the shiitake mushrooms, enoki, and shimeji. Sprinkle with salt. Sauté for another 4-5 minutes until everything is golden and aromatic.
Once the mushrooms have cooked down, toss in the mizuna. Stir gently until the greens are wilted but still vibrant. This should take just a couple of minutes.
In a small bowl, combine the sesame seeds, rice vinegar, mirin, sugar, soy sauce, and ginger. Whisk until well-blended. Taste it – adjust the seasoning if needed.
Transfer the warm mushroom mixture into a large bowl. Pour the sesame dressing over it. Mix gently, so all mushrooms and greens are nicely coated.
Serve immediately for warm salad goodness, or let it cool down and serve it chilled. Either way, you’re in for a treat!