Cut the onion, potato and carrot into small chunks before adding them to a large pan half filled with water.Bring the water to boil and then simmer for 20 minutes or until the vegetables are soft. It is a good idea to start cooking your rice now.Remove the saucepan from the heat. Add 4-5 blocks of curry roux to the pot with vegetables. Turn on the heat to low and allow to simmer for 10 minutes. Keep mixing until the curry sauce is thick and smooth.While the curry is infusing, season your chicken breast pieces with salt and pepper before covering with flour first and then raw egg, then panko breadcrumbs.Heat up the oil in a separate saucepan to 180°C and carefully lower the cutlets into the oil and cook them for a few minutes on both sides until they become a golden brown colour.Slice the cooked chicken katsu into strips and lay over a bed of rice before adding the curry sauce. Garnish with fukujinzuke pickled radish, tonkatsu sauce, and boiled egg halves. Enjoy.