Preheat the oven to 180° C / gas mark 4

Remove the stems from the mushrooms. An easy way to do this is to cup one in your writing hand, stem up, and gently but firmly twist and pry the stem out. Then use a small spoon to remove any remaining stem. Do not discard the stems; chop them up small and set them aside. It’s common to break a mushroom or two, which is why the recipe calls for twenty-two mushrooms but stuffs twenty. If one breaks and can’t be used, just chop it up along with the stems.

If you don't break them whilst removing the stem, then finely chop the two extras anyway.

Preheat a large frying pan over a medium heat. Pour in the peanut oil and sauté the chopped mushroom for about 3 mins, until some moisture has released. Add the diced daikon (celery etc) and cook for 5 more minutes, stirring often. Add the garlic and cook for a minute longer.

At this point, lots of moisture should be released from the mushrooms. Add the mirin (rice wine), salt, and white pepper, and cook for about 2 minutes. Turn off the heat and add the panko (breadcrumbs) in 1/2-cup batches and stir, alternately adding the sesame oil and splashes of water (up to 4 tablespoons) until all the bread crumbs are moist. The mixture should be crumbly but, when you press some between your fingers, it should hold together. Mix in the scallions and adjust the salt to taste.

Grease a baking sheet with a little sesame oil. Stuff each mushroom with the filling and place on the baking sheet. To stuff them, place a little of the filling into the mushroom crevice and then add another tablespoon on top of that, pressing firmly to form a mound.

Bake for 20 minutes. To serve, sprinkle the toasted sesame seeds over the mushrooms and drizzle with a little sesame oil, if desired.