Wrap 350 g firm tofu with kitchen paper and place it on a heatproof plate. Microwave for 2 minutes at 600W, then remove and leave to cool.
Heat a pan on medium and add a drizzle of cooking oil. Fry 50 g green bell pepper(s) and 50 g Japanese leeks (naganegi) until lightly charred, then transfer to a plate and set by the stove for later.
Once the tofu is cool to the touch, cut it into cubes. Larger cubes will make cooking easier later.
Take a small bowl and add a generous pinch of salt and pepper and 3 tbsp potato starch, mix well and sprinkle it on a plate or tray.
Reheat the same pan as earlier over medium and add a generous amount of cooking oil (approx 1 tbsp per serving). Once the pan is hot, coat the tofu pieces in the starch mixture and place them directly into the pan. Tip: Do not coat the tofu in advance as the starch will soak up the moisture and become sticky.
Fry the tofu and turn occasionally, ensuring they're golden brown on all sides.
Take a small bowl and mix 2 tbsp soy sauce, 2 tbsp mirin, 2 tbsp sake, 2 tsp sugar and ½ tbsp garlic paste until well combined. Once the tofu is golden all over, pour the sauce into the pan.
Add the charred vegetables from earlier and continue to cook until warmed through and the glaze has become thick and glossy. Once everything is evenly coated, remove the pan from the heat.
Divide 2 portions cooked Japanese short-grain rice into serving bowls and place the tofu and vegetables on top. Sprinkle with sesame seeds, finely chopped green onions and a drizzle of chili oil.
Enjoy!