Pork Cutlet: flatten your pork pieces so that they are even in thickness for even cooking. Prepare your breading station of flour, beaten eggs and panko breadcrumbs. Coat your pork cutlets in the flour, then eggs and lastly panko breadcrumbs - making sure all surfaces are evenly coated.
Frying: bring a pot of neutral/vegetable oil to frying temperature (375F/190C) and carefully drop in the pork cutlets. Fry until golden brown. Place on a wire rack and let excess oil drip off.
Wasabi mayo: in a bowl, combine the kewpie mayo and wasabi together.
Assemble: remove the crust off of the sandwich slices. Spread a generous layer of wasabi mayo onto one slice of bread, top with shredded cabbage, fried pork katsu and tonkatsu sauce. Close the sandwich and enjoy!