Thinly slice the pickled cucumber and squeeze out the moisture thoroughly.
Drain the oil from the tuna using a sieve, then mix the tuna with mayonnaise.
Julienne the carrot, add a pinch of salt, and sauté in a pan with some oil.
Lay out the seaweed sheet and spread the rice thinly and evenly over it.
Place the pickled cucumber, tuna, and sautéed carrot on top of the rice.
Roll the gimbap tightly to shape it.
Cut the roll into bite-sized pieces.