Make a central cut in the chicken and butterfly as if opening a double door. Season with salt and pepper. Coat with the flour, then the egg, and lastly cover with panko. Cut the cabbage into thin strips and soak in water.
Make the miso sauce. Combine the ★ ingredients in a heat-resistant dish and microwave for 2-2 1/2 minutes.
Pour the oil into a frying pan and heat it up. Deep-fry the chicken. To make it nice and crispy, fry them on medium heat and then slowly raise the heat to high at the very end.
Cut into slices and arrange on a dish. Pour over the miso sauce.