Preheat a frying pan with some olive oil.
Sear for 1-2 minutes on each side, it should be rare in the middle.
Take out of the pan and put on a plate.
Combine the ingredients for the marinade in a bowl.
Put the steak in a plastic bag and add the dressing to it. Make sure the whole steak is covered by the marinade. Place in the fridge and let it rest for at least 3 hours, but preferably over night.
When time to serve, slice the cucumber, red bell pepper and carrot thinly.
Take out the steak from the plastic bowl and brush off some of the excess marinade.
Slice thinly (1/2 cm thin slices), add cucumber, bell pepper and carrot on each slice and roll together.
Place on a big plate.
Pour pozu to a bowl or combine the ingredients for the ponzu style sauce in a bowl and serve.