Cut the king oyster mushroom in half lengthwise, then cut horizontally into half again. Slice into 5mm thick strips.

Pat the fried tofu with a paper towel to remove excess oil, then cut into 1cm wide strips along the longer edge.

In a microwave-safe container, combine the canned tuna, fried tofu, king oyster mushroom, and seasonings. Mix lightly, cover loosely with plastic wrap, and microwave at 600W for 2 minutes and 30 seconds.