In a large bowl, combine the ingredients for Bulgogi marinade (1 Tbsp sesame oil, 2 Tbsp soy sauce, 2 Tbsp brown sugar, and freshly ground black pepper). Grate ¼ of Asian pear (2 Tbsp after grated), crush (or mince) 4 cloves garlic (2 tsp minced garlic), and mix all together.
Cut the onion into thin slices. Cut the carrot to 2” (5 cm) pieces, then cut into julienned pieces.
Cut the scallions into 2” (5cm) long pieces and cut the beef into thin 2” (5 cm) long strips slices. I put the meat in the freezer for 2 hours (depending on the size and thickness) prior to cutting the meat into thin slices (see my tutorial on how I slice my meat).
Toss the vegetables and meat together and coat with the marinade. Set aside for at least 20 minutes.
Bean Sprouts & Spinach (optional)
Prepare 2 medium bowls; in each bowl combine 1 Tbsp sesame oil, ½ tsp of minced garlic (1 clove garlic), and a pinch of kosher salt and mix well.
Bring a medium pot of water to a boil and add 1 tsp salt. Add the bean sprouts and cook for about 1 minute. We will need to reserve the boiling water for spinach, so scoop up the bean sprouts with a sieve or spider strainer. Run in cold water in the sink to stop cooking further with remaining heat and drain well. Set aside.
In the same boiling water, blanch the spinach for 30 seconds. Prepare iced water in a large bowl and transfer the spinach to the iced water to stop cooking.
Squeeze out water from spinach as much as you can and add to one of the bowls with seasonings. Toss well with the sauce.
Thinly cut the green onions. Add the bean sprouts and green onion in the other bowl and toss well with the sauce.
Carrot & Shiitake Mushrooms (optional)
Cut the carrot in half widthwise, about 2” (5 cm) length. Cut each piece into thin slices, and julienne the carrots. Cut the shiitake mushrooms into thin slices.
Heat 1 tsp sesame oil in a large frying pan and add the carrot. Season with a pinch of salt and sauté till tender. If your pan is big enough to add shiitake mushrooms, move the carrot to one side when it’s cooked halfway. Add 1 tsp sesame oil in the open space and add shiitake mushrooms. Season with a pinch of salt and sauté till tender. If your frying pan is small, cook one ingredient at a time; transfer the carrot to a plate and cook shiitake mushrooms after. When carrot and shiitake mushrooms are both tender (but not overcooked), transfer to a plate and set aside.
Heat 1 Tbsp cooking oil in the large frying pan and make fried eggs. I cook the eggs “over hard” so egg yolk won’t be runny and messy when onigirazu is cut in half.
Grill the Meat
In a large skillet (I use a griddle pan so I can grill the meat in a single layer), heat 1 Tbsp sesame oil over medium-high heat and sauté the marinated beef until cooked, about 5 minutes. Transfer the meat to the plate and sprinkle with sesame seeds.
Gochujang Sauce (optional)
Combine all of the sauce ingredients in a small bowl and mix them all together. Add 1-2 Tbsp water until you achieve the consistency you like.
Place a plastic wrap on a working surface and put a sheet of nori seaweed on top (shiny side facing down), with a corner pointing up. Evenly spread the steamed rice in a thin layer and form into a square shape in the center of the nori sheet. If you make onigirazu with different ingredients that have more mild taste, sprinkling salt at this step is very important, especially if you planning on eating it at room temperature.
Place Bulgogi on top of the rice in a thin layer. Then put spinach, bean sprouts, carrot, and shiitake in a thin layer on top of the meat.
Add the fried egg and then steamed rice on top. Try to keep the square shape as you spread the rice evenly in a thin layer.
Bring left and right corners of nori sheet towards the center. Fold gently but tightly to wrap around the layers at the center.
Then bring bottom and top corners towards the center. Continue to fold gently but tightly around the layers. Make sure the rice is tucked in nicely. If you like the onigirazu to showcase the ingredients after cutting in half, mark with a piece of carrot perpendicular to the ingredients (see video). Flip over and shape the onigirazu gently. Wrap with plastic wrap tightly and set aside for 5 minutes.
Cut the onigirazu with a sharp knife (following your “carrot” mark). Run your knife in cold water before cutting so that the cross-section will be clean.
If you plan to make it ahead of time, wrap the onigirazu with a kitchen towel and keep in the refrigerator overnight. The towel will prevent the rice from getting harder from cold air.