Slice the flounder diagonally into bite-sized pieces. Squeeze out the lemon juice. Grate the ginger.
Mince or finely chop the shiso. Remove the seeds from the chili pepper and mince (this is easy using kitchen scissors).
Combine Steps 1 and 2 in a bowl together, add the rock salt and mix together well. Chill in the refrigerator for 2 hours. Flavor with salt (if necessary) before serving.
It's even better if you mix it while chilling. The acidity of the lemon will turn the outside of the sashimi white.
Story Behind this Recipe
I wanted to eat something light and refreshing on a hot and humid day. I like olive oil and sesame oil, but I didn't use them in this recipe.
-This is best served soon after cooking, or up to 2 hours after. It's best not to let it sit for too long. -If you also use the scallop's mantle, it's good to use a lot of salt. -This recipe also works well with sea bream or other white meat fish. -Be sure to use freshly squeezed lemon juice.