Cook the rice using a little less water than usual. Fresh cooked rice is best for gimbap.
Cut the tofu into about 3/4-inch thick sticks. Pat dry with a paper towel, and lightly sprinkle with salt. Heat a small pan with enough oil to cover the pan. Add the tofu pieces and fry until all sides are golden brown.
Bring a large pot of water to a boil over high heat, and prepare an ice bath. Blanch the spinach, place immediately in the ice bath, then squeeze out the water. Cut into short lengths by running a knife through a few of times. Season with the sesame oil (about 1/2 teaspoon) and salt.
Cut the cucumber into 1/2-inch thick sticks. Do not use the seedy part. Heat the pan with a little bit of oil over medium high heat. Stir fry the cucumber until softened. Lightly season with salt.
Julienne the carrots. Heat the pan with a little bit of oil over medium high heat. Stir fry the carrots until softened. Lightly season with salt.
When all the other ingredients are ready, remove the rice from the rice cooker. While the rice is still hot, add the sesame oil and salt. Mix well by gently folding with a rice paddle or large spoon until evenly seasoned. Add more salt to taste. The rice will cool down during this process and be ready to be used.
Put a sheet of gim, shiny side down and longer side toward you, on a cutting board or a bamboo mat if available. Spread about 3/4 cup to 1 cup of rice evenly over the gim, using a rice paddle or your fingers preferably. Lay the prepared ingredients on top of the rice close to the side toward you.
Lift the entire bottom edge with both hands and roll over the filling away from you, tucking in the filling with your fingers. Put firm pressure over the roll with the help of the bamboo mat, if using, to close everything in tightly. Then, continue to roll again, putting pressure evenly over the roll using both hands.
Rub or brush the roll with a little bit of sesame oil for extra flavor and shiny look. Apply a little bit of sesame oil to a sharp knife. This will keep rice from sticking to the knife. Repeat as necessary after each cut. Wipe the knife with a damp towel if the rice still sticks. Cut the roll into 1/2-inch thick bite sizes.
Mix 1 cup regular short grain rice with 1 cup short grain brown rice for a healthier option.Adapted from Temple Food of Venerable Seonjae