Bring 1 cup of dashi, 2 tablespoons of soy sauce, and 2 tablespoons of mirin to a simmer. Turn off the heat and cover.
Grate 1 piece of daikon, about 2in / 5cm long, and squeeze out the excess liquid. Thinly slice 2 scallions.
Drain 395g of medium-firm tofu, pat dry and cut into large cubes. Heat 2 cups of neutral oil in a small deep pan to 320-340°F / 160-170°C.
Coat a few cubes at a time in 4 tablespoons of potato starch right before frying. Fry about three at a time, turning once, until light golden and crisp. Drain on a rack.
Place the tofu in shallow bowls and pour the warm sauce around it. Top with the daikon, scallions, and 1 teaspoon of grated ginger.
