Prepare the Peppers: Wash the Shishito peppers and pat them completely dry. (Crucial: Use a knife to carefully poke a tiny hole in each pepper so they don't explode from steam build-up in the hot pan).

Heat the Pan: Heat a heavy cast-iron skillet over high heat until it is smoking hot. Add the toasted sesame oil.

Blister the Peppers: Toss the dried peppers into the hot pan in a single layer. Let them cook undisturbed for 1 to 2 minutes until the bottoms are heavily blistered, charred, and blackened. Shake the pan to flip them and blister the other side for another 1 to 2 minutes until they soften slightly.

Season and Glaze: Turn off the heat. Immediately splash the soy sauce directly into the hot pan (it will instantly sizzle and evaporate, leaving a sticky glaze on the peppers). Toss aggressively.

Garnish and Serve: Transfer the blistered peppers to a serving plate. Sprinkle heavily with flaky sea salt and top with a generous handful of Katsuobushi. The heat will make the bonito flakes dance. Serve instantly.