To press the tofu, slice the tofu into 12 equal size pieces. Lay a dish towel on a sheet pan and lay out the tofu slices. Place another towel on top along with another sheet pan and something heavy to press it down. I usually place a few cans on top for weight. Press the tofu for 1 hour.

In a saucepan over medium high heat, bring the water and kombu to a boil then down to a simmer. Add the bonito flakes and simmer for 5 minutes. Remove from heat and set aside, covered, for another 10 minutes.

Strain the broth and discard the kombu and flakes. Add the soy sauce and mirin. Keep warm while you fry the tofu.

Have enough oil in a pot over medium heat. Roll the slices of tofu in cornstarch. Once hot (350F), fry the tofu until crispy. It should just have a very light golden color. Place the fried tofu on a paper lined sheet pan to dry.

Right before you serve, place the tofu in your serving dish and pour a generous amount of broth on top. Garnish with green onions, ginger, or more bonito flakes. Serve immediately.