Turn grill to high heat.
Toss Shishito peppers in oil and season with a pinch of salt and pepper.
When hot, place peppers on the grill and let them cook several minutes until starting to char. Flip the peppers over and continue to cook for several minutes.
Remove from heat and toss in ponzu. Arrange on a plate and sprinkle with sea salt. Top with bonito flakes, sesame seeds and scallion.
For the Lime Ponzu
Mix all ingredients until sugar is dissolved.