Cook 3 cups of short-grain rice without soaking, using slightly less water than usual.
Marinate 225g of thinly sliced beef for 20 minutes in 1½ tablespoons of soy sauce, half of the 4 teaspoons of sugar, 2 teaspoons of rice wine, 2 teaspoons of sesame oil, 1 teaspoon of minced garlic, and a little black pepper.
For the sauce, mix 4 tablespoons of gochujang, the remaining sugar, half of the 2 tablespoons of sesame oil, and 1 tablespoon of water.
Halve 2 small cucumbers lengthwise and thinly slice. Toss with ½ teaspoon of salt, leave for 10-15 minutes, and squeeze dry.
Boil 225g of soybean sprouts for 2-3 minutes and drain. Blanch 225g of spinach in salted boiling water for about 40 seconds, rinse in cold water, squeeze dry, and cut into 3in / 7.5cm lengths.
Season the sprouts, spinach, and cucumber separately, dividing the remaining sesame oil, 1½ teaspoons of minced garlic, and 1½ teaspoons of sesame seeds among them.
Mix 2 tablespoons of chopped scallion into the spinach and cucumber, and season the sprouts and spinach with salt.
Sauté 115g of thinly sliced shiitake mushrooms, then 2 medium julienned carrots, in a lightly oiled skillet over medium-high heat until softened, seasoning each with a pinch of salt.
Stir-fry the beef over high heat for 2-3 minutes. Divide the rice among bowls, top with the vegetables and beef, and serve with the sauce.
