Finely chop the shiso leaves. In a bowl, mix the cooked rice, chicken broth powder, salt and pepper (for rice), and chopped shiso leaves.

Lay out the beef slices on a piece of plastic wrap and sprinkle with salt and pepper (for meat). Place the rice mixture on the edge of the beef and shape it. Use the plastic wrap to tightly roll the beef around the rice.

Heat sesame oil in a frying pan over medium heat. Place the beef rolls seam-side down and cook for about 1 minute. Rotate the rolls to cook evenly on all sides, then remove from the pan.