Combine the first 9 ingredients of the BULGOGI (through black pepper) in a blender or food processor until smooth. Add water or apple juice as needed for consistency.
In a gallon-size resealable plastic bag, combine apple mixture, steak, and green onion. Seal and chill until ready to cook.
Meanwhile, combine all SAUCE ingredients in a small bowl, set aside.
In a large nonstick skillet, heat 1 teaspoon vegetable oil over medium-high heat. Add mushrooms and cook until tender, 3 to 4 minutes. Season to taste with kosher salt. Remove from skillet. Add remaining vegetable oil and repeat steps with carrots.
In the same large skillet, heat 2 teaspoons sesame oil over medium-high heat. Add half of the green onions and garlic. Add spinach in batches, making sure the previous batch is fully wilted before adding more. Season to taste with kosher salt. Remove from skillet. Add 2 teaspoons toasted sesame oil and repeat steps with mung bean sprouts.
In the same large skillet, heat 2 teaspoons sesame oil over medium-high heat. Add rice and cook until just toasted. Remove from skillet.
Transfer the meat and marinade to the skillet and cook over medium-high heat until browned and cooked through, about 5 minutes.
Divide rice among 4 bowls.
Arrange the mushrooms, carrots, spinach, bean sprouts, kimchi, cucumber, and nori around the edge of the bowl. Place the meat in the center and top with the egg. Top with SAUCE and sesame seeds.