Cut a 1cm border around the edges of the thick fried tofu and scoop out the center with a spoon. Roughly chop the scooped-out portion. Thinly slice the shiso leaves.

In a bowl, mix the chopped tofu center, tuna, and soy sauce.

Place the tofu shell on a baking tray, crack an egg into the hollowed-out center, add the tuna mixture, and top with a slice of cheese. Bake in a toaster oven for about 10 minutes.