Make a thin incision around the top of the eggplant and along with the eggplant lengthwise at 3 locations so that it’s easier to peel off the skin later (think peeling a banana).
Insert a chopstick or skewer to create a hole, which helps to evaporate moisture while cooking.
Grill the eggplant on high heat over the wire rack. Do you see the steam coming off from eggplant? Grill until the skin gets completely burnt and the entire eggplant becomes wilted. Remove from the heat.
Dip your fingers in iced water and start peeling the skin off. You can peel off the skin similar to a banana since there are several incisions already made. You have to peel it off quickly before the purple skin color transfers to the nice green eggplant color inside.
Cut into small pieces and serve on a plate.
Sprinkle katsuobushi (bonito flakes) and green onions. I also put some Korean chili thread. Serve with Ponzu and Yuzu Kosho, or soy sauce and grated ginger.
The Broil Method
Set the oven broiler to high (550 ºF/288 ºC) for 3 minutes before cooking. After step 3 above, place the eggplant on a baking sheet and put in the middle rack of the oven, about 6" (15 cm) away from the heating element. Cook for 10-15 minutes, and then flip to cook the other side for 10 minutes, until the inside is tender and cooked through. Watch the eggplant carefully; if your oven is small/strong, try broiling at medium (500 ºF/260 ºC).
You can keep the leftovers in an airtight container and store in the refrigerator for up to 2 days.