Place the mushrooms in a bowl with the dashi granules and sesame oil. Use your hands to evenly coat the mushrooms with the granules and oil.
Fry the mushrooms:
Heat 1 teaspoon neutral oil in a small skillet over medium-high heat. Once very hot and shimmering, add the mushrooms and cook without moving for 3–5 minutes. Flip and cook an additional 3–5 minutes until the mushrooms are well-browned and any excess moisture in the skillet has evaporated.
To serve:
Transfer the mushrooms to a serving platter and sprinkle minced scallions or sesame seeds on top. Enjoy!