Heat a drizzle of sesame oil in a pot on medium-high heat. Cook ginger and first measure of sesame seeds for 1-2 minutes, until fragrant. Add rice, water measure and ¼ tsp salt and bring to the boil. Once boiling, reduce heat to low, cover and cook for 15 minutes. Remove from heat and leave to steam, covered, for a further 8 minutes. Fluff grains with a fork and season to taste.
Pat tofu slices dry with a paper towel. Place tofu onto a lined oven tray and brush both sides with bulgogi sauce. Bake on upper oven rack for 15-20 minutes, until golden and tender. Season to taste.
Toss shiitake mushrooms in a bowl with garlic, soy sauce and a drizzle of sesame oil, until mushrooms are well coated. Transfer to a lined oven tray and bake on rack below tofu for 15-20 minutes, until golden and tender.
Serve rice topped with veggies, tofu and roasted shiitake mushrooms. Drizzle with remaining bulgogi sauce and garnish with sesame seeds and spring onion.