- Wrap the tofu with 2-3 layers of paper towel. Place a plate on top to drain the water from the tofu for 15 minutes.
- Meanwhile, combine the water and the kombu in a small saucepan and bring it to boil. Just before the water begins to boil, when you see small bubbles around the edges of the pot, remove the kombu. This liquid is called Kombu dashi. If you are vegetarian or vegan, use this dashi and skip the next step.
- Add katsuobushi into the saucepan and cook for 15 seconds, and then turn off the heat. Let it steep for 15 minutes. Katsuobushi will slowly settle to the bottom of the saucepan. Drain the katsuobushi over a fine sieve (skip katsuobushi if you are vegetarian).
- For dipping sauce, add mirin in a saucepan and bring to boil to evaporate the alcohol.
- Add dashi and soy sauce and bring to a boil. Turn off the heat and set aside.
- Chop the green onion. Peel and grate ginger. Set aside.
- Peel and grate the daikon and gently squeeze water out. Set aside.
- Heat the cooking oil to 350°F in a medium saucepan or deep fryer. Remove tofu from the paper towel and cut into 6 equal size pieces.
- When the oil reaches 350°F, coat the tofu with potato starch. Make sure tofu is covered nicely with potato starch. If you don’t cover well, the moisture inside tofu might come out while deep frying and it will splatter.
- Deep fry the tofu squares until they are light brown and crispy. Tofu can be eaten directly from the package so you don’t have to worry about cooking through. Make sure that oil temperature is optimal. The shell/coating will absorb too much oil at low temperature. Remove the tofu and drain excess oil on a plate lined with paper towel or wire rack.
- To serve, re-heat the sauce and place the tofu in a serving bowl. Garnish with green onion, grated daikon, ginger, and pour the sauce. Sprinkle with shichimi togarashi (Japanese 7 spice) if you like some spicy kick.