Pat dry the salmon fillet with paper towels and cut into thirds.

Cut the tofu into six pieces. Trim the roots of kaiware sprouts and cut them in half. Mince the green onion and ginger.

Layer tofu and salmon alternately in a flat microwave-safe container. Drizzle sake and sprinkle salt and pepper. Cover loosely with plastic wrap and microwave at 600W for 5 minutes until salmon is cooked through.

Mix minced green onion, ginger, and all spicy sauce ingredients in a bowl.