Cut the seared bonito into 1cm slices. Sprinkle with salt and pepper, then coat both sides with potato starch.

Thinly slice the red bell pepper and onion. Julienne the ginger and soak it in water, then drain.

In a bowl, mix sugar, ponzu soy sauce, and water. Add the sliced red bell pepper and onion, and mix well.

Heat salad oil in a frying pan over medium heat. Add the bonito slices and quickly sear both sides until browned.

Add the seared bonito to the bowl with the vegetables and sauce. Mix gently and refrigerate for about 10 minutes to let the flavors meld.