Drain the water from the firm tofu. How about an easy method using the microwave? Please refer to.
Combine the sauce ingredients marked - the sake, mirin, and soy sauce. Slice the leek thinly on the diagonal.
Cut the pork belly slices in half. Cut the drained tofu into 4 pieces vertically and 4 pieces horizontally for a total of 16 pieces.
Season the meat with salt and pepper, and coat on just one side with the flour. Wrap the meat around the tofu.
Put the rolls from Step 4 in a frying pan, and pan fry until well browned on one side.
Turn the rolls over with a spatula, and brown on the other side also.
When all sides are browned, add the sauce mixture from Step 2.
Add the leek and mix gently. Put on a lid and steam-fry for 1 minute.
Take the lid off and cook the sauce down. When the sauce has reduced and thickened a bit, turn off the heat. It's done.
The tofu is fragile so put on serving plates with a spatula. Sprinkle with some shichimi spice if you like. Bon appetit.