Prepare the pork. Make small cuts at 2cm(0.78inch) intervals along the edge of the pork in order to avoid the pork curling up when its fried.
Using a meat mullet, bash the meat to flatten to about 1cm(0.39 inch) thick.
Season the pork with salt and pepper
Prepare the batter. Combine egg, water and mayonnaise in a mixing bowl.
Add plain flour to the egg mixture bowl and mix them briefly with chopsticks. Be careful not to over mix it.
Prepare the batter bowl, a tray of panko crumbs, and another tray to place the coated pork.
Dip a piece of pork into the batter and coat well with batter. Remove excess batter and move it to the tray of panko crumbs.
Coat the pork with panko crumbs on both sides well by pressing down to adhere and also make sure that all sides of the pork are covered.
Place the panko crumbed pork to the last tray and repeat the process for the rest of the pork.
Heat the deep frying oil in a deep frying pan or deep fryer (like I did) to 170 degree celsius(338F). At the same time line kitchen paper on a wire rack on a tray.
When the oil reaches the temperature, gently put one pork in. Cook one at a time.
Deep fry the pork for a few minutes without moving it around, when the edge becomes golden brown, flip it over gently and carefully with chopsticks and heat up to 190 degree celsius (374F) to cook for a further 2-3 minutes till golden brown.
Drain the deep fried pork on the kitchen paper-lined wire rack. Cook the rest of crumbed pork in the same way.
Slice the deep fried pork into 1.5cm(0.59 inch) strips and move all pieces in one go by placing the knife underneath the cut pork. *4
Serve with finely shredded cabbage, shiso leaves and tomato.
Pore the tonkatsu sauce over the pork.
*1 The pork I bought comes in 3 sirloin steaks weighing about 400 g*2 If you are unable to find Japanese Panko crumb, you can make your own. Pulse white crusty bread in a food processor and spread them onto a tray. Allow them to dry until crisp. *3 50g oil was absorbed, but you will need about 500g or more depending on the size of your deep frying pan. *4 Japanese people use chopsticks so any large meat or food is usually cut into smaller sizes so that its easy to use chopsticks.*5 If you are unable to access to Tonkatsu sauce. Make your own. Combine 1 tbsp Worcestershire sauce, 1 tbsp of tomato ketchup and 1 tsp of mirin. *6 Tonkatsu can be dressed with miso sauce which is called Miso Katsu.