Prepare the brown rice.
Lay out the seaweed sheet for kimbap.
Spread the brown rice thinly and evenly on top of the seaweed.
Drain the oil from the canned tuna and get it ready.
Mix the tuna with mayonnaise and pepper.
Place the tuna, cucumber, carrot, pickled radish, and egg garnish on top of the rice.
Arrange the ingredients so they're spread out evenly.
Roll the kimbap up tightly.
Seal the edge of the seaweed with a bit of water.
Cut into bite-sized pieces.