In a bowl, mix the Red Miso Paste, sugar, lime, vinegar, ginger, garlic, chilli, coriander, and sesame oil together. Rub over the pork. Leave to marinade for 20 minutes.
Preheat a griddle pan over medium-high heat.
Add the veg oil to the pan with the pork fillet, reserving the excess marinade for use in the next step. Cook for 4 minutes on each side until it begins to char.
Add the remaining miso to the pan and roll the pork fillet in the glaze and cook until the sauce reduces to a glaze.
Remove the pan from heat, and allow the pork to rest for 5 minutes in the sticky glaze.
Sprinkle the sesame seeds over the pork. Slice the pork fillet into 2 cm thick slices, and serve with the pan juices poured over the pork.
Serve with japense rice, and bak choi.