To CookHeat frying pan over medium-high heat. Pan-fry the tofu slices until golden brown and set aside to cool.To assemble, place a cling wrap on a chopping board and put a sheet of nori seaweed on top (shiny side facing down).Evenly spread the steamed rice (thinly) to form into a square shape in the centre of nori sheet. Sprinkle a little bit of salt. Place the shredded cabbage evenly on top of rice and then the fried tofu on top.Spread the mustard and tonkatsu sauce on the tofu and flip the tofu so the sauce is on the cabbage.Place another thin layer of steamed rice on top of the tofu. Fold left and right corners of nori sheet towards the centre. Fold gently but tightly to wrap around the layers at the centre.Then fold bottom and top corners towards the centre. Fold gently but tightly around the layers. Ensure the rice is tucked in nicely. Wrap with cling wrap tightly and set aside for 3 mins.Cut the onigirazu with a sharp and clean knife. Run your knife in cold water before cutting so that the cross-section will be clean.