1. Heat the oil in a frying pan over medium heat and fry onion until translucent and golden brown. Set aside to cool.
2. In a bowl, add ground pork, cooled onion from #1, and all the ingredient A. Knead well with your hand until the meat mixture becomes sticky.
3. Scoop some of meat mixture and shape into an oval shape patty and place on a plate. Coat with flour, then egg, and panko/bread crumbs. Let rest in the fridge for about 15 mins.
4. Gently place the menchi-katsu into the oil. For the first 1~2min, don’t touch them as they are soft and would break up easily. Turn them and deep-fry until all sides are light brown and crispy or until the juices run clear when pierced with a bamboo skewer.
5. Transfer to a plate lined with paper towels to drain excess oil.