Place the rice in a sieve and set the sieve in a bowl. Add water, then gently rub the rice between your hands. The water should become milky. Discard the water. Repeat until the water becomes relatively clear. Drain the rice for 30 minutes.
Transfer the rice to a heatproof bowl (preferably metal as ceramic may crack over time) that can be fitted in a pot. Add the 185ml of water and set aside to let the rice soak for at least 30 minutes.
Fill the pot with a bit of water, about 1/2 to 3/4-inch tall. Place the bowl of rice inside. Cover the pot with lid and turn on the heat to high. Once the water in the pot (not in the rice) has come to a boil, reduce the heat to low and simmer for 15 to 20 minutes until all the water has been absorbed. Try not to open the pot cover while the rice is simmering.
After all the water has been absorbed, turn off the heat and let the rice steam in residual heat for 10 minutes.
Tip the rice out into a bowl and stir in the sesame oil and sesame seeds. Cover with a damp tea towel and set aside.
Filling
Egg: Beat the egg with a bit of salt, fry into an omelette in a non-stick pan and slice into strips.
Carrot: Heat 1 teaspoon oil in a frying pan (preferably non-stick). Add in the carrot and a pinch of salt and cook until carrot has softened.
Meat (tuna steak): Season tuna steak with salt and freshly ground pepper on both sides. Heat a pan with 1 tablespoon oil and pan-fry the tuna steak until cooked, flipping it once.
Meat (chicken/pork): Cut the meat into slices, and marinate with 1 tablespoon light soy sauce, 1/2 tablespoon sesame oil, 1/2 tablespoon sake and 1/2 tablespoon brown sugar. Heat a pan with 1 tablespoon oil and stir-fry the meat until cooked.
Spinach: Boil a pot of water and season with a generous pinch of salt. Add in the spinach and blanch until spinach has softened. Drain the spinach and after it has cooled down slightly, squeeze the spinach to remove excess water.
Cucumber: Cut the cucumber into long strips.
Assembly (See step-by-step photos for illustration.)
If desired, toast the nori on a non-stick frying pan over medium heat until warmed through.
Place the nori on a bamboo rolling mat, rough side up.
Spread half the rice on the nori, leaving some spacing at the top then top with desired Filling.
With the help of the bamboo mat, roll up the gimbap tightly, making sure the start of the rice meets the end of the rice to make a nicer looking roll.
Stick a few pieces of rice on to the end of the nori (to help sticking) then roll it up. Use the bamboo mat to help to keep the roll tight - but don't squash it too hard until it goes out of shape.
Repeat to make the second roll.
Cut the rolls into 6 to 8 pieces each, wiping the knife with a damp cloth after before each slice. Serve immediately.
NOTES
160 grams rice is approximately 1 rice cooker cup of rice (180ml; 3/4 cup)
It may not be easy to roll the gimbap tightly at the start, just keep practicing!
If you cannot finish all the gimbap, store them in an airtight container in the fridge. The next day, beat an egg, dip the cut sides of gimbap in the egg and pan-fry until the egg is cooked. This way, your gimbap will not taste dry and hard!