• Gather all the ingredients.
  

To Make the Sesame Dressing

• Toast 3 Tbsp toasted white sesame seeds in a frying pan (without oil) until fragrant, about 3–5 minutes. Swirl and shake the pan once in a while for even toasting.  Transfer the toasted sesame seeds into your Japanese mortar and pestle. Grind the sesame seeds about half way (this adds texture to the dressing). If you don’t have a Japanese mortar and pestle, you can use a food processor or grind between your palms.
  
• Combine 3 Tbsp rice vinegar (unseasoned), 1 Tbsp mirin, 1 Tbsp sugar, and 2 Tbsp soy sauce. Then, mix in the toasted sesame seeds.
  

To Prepare the Ingredients

• Remove the end of 9.5 oz king oyster mushrooms (eringi) and cut the mushrooms in half, about 2 inches (5 cm) long. Then, cut them into slices.
  
• Discard the stems from 5 shiitake mushrooms and cut into thin slices.
  
• Cut off and discard the base of 7 oz enoki mushrooms and cut them in half crosswise. Then, separate them into small clusters with your fingers.
  
• Cut the base of 3.5  oz shimeji mushrooms and separate into small clusters by hand.
  
• Discard the end of 1 bunch mizuna (Japanese mustard green) and cut the mizuna into pieces 2 inches (5 cm) long.
  

To Cook the Mushroom Salad

• Heat 1½ Tbsp neutral oil in a large frying pan over medium heat. Add all the mushrooms to the pan.
  
• Sauté the mushrooms and add ½ tsp Diamond Crystal kosher salt. Then, add 1 Tbsp sake and cook covered for 2 minutes over medium-low heat.
  
• Add the sesame dressing and toss to coat. Drizzle 1 tsp toasted sesame oil and mix it all together.
  
• Right before turning off the heat, add the mizuna and quickly toss all together. The remaining heat will continue to cook the mizuna, so don’t worry that it still looks raw. Transfer to a serving dish and serve hot.
  

To Store

• You can keep the leftovers in an airtight container and store in the refrigerator for up to 3 days and in the freezer for 2 weeks.