Rinse and cut off the top of the eggplant. Then chop the eggplant rangiri-style by rotating the eggplant (see vide) into equal size pieces. Transfer to a bowl of cold salted water and let it rest for 5 minutes.
In the meantime, slice the tofu into bite sized squares. Pat it dry and then coat all sides with potato starch. Over medium high heat, add some oil and cook the tofu on each side until golden brown (about 45-60 seconds per side). Remove from pan.
Drain the eggplant well. Over medium to medium high heat add 1 tbsp of cooking oil to the pan and then add the eggplant. Let eggplant soak up the oil (the eggplant will soak it up relatively quickly). Key point: As soon as the oil is absorbed by the eggplant, flip the them so that the skin side is facing down. This will help maintain the purple colour while still achieving some nice charring. Once the skin side is nice and brown, flip onto the other side and fry until light golden brown. In the meantime, dissolve the miso paste with the mirin.
Then add the sake, sugar and kombu mentsuyu and swirl the pan around 1-2 times. Add the tofu and let it cook until most of sauce is absorbed by the eggplant and tofu. Turn heat down to medium low and then add in the miso and chili bean paste. Key point: adding miso toward the end will ensure it doesn't burn and retains its flavour. Swirl the pan and then let it cook for 30-45 seconds to allow the eggplant and tofu to absorb the remaining sauce. Flip the tofu as needed to ensure the sauce coats everything.
Turn off the heat, transfer to a plate and then garnish with sesame seeds and scallions. Serve with rice or grain of choice and enjoy!
Nutritional Information Disclaimer: Nutrition information is a rough estimate calculated on an online tool (Cronometer).