Cut the tofu into bite-sized pieces.
Tear the mushrooms into small strips.
Julienne the onion and green onion.
Pour cooking oil into a pan and grill the tofu on both sides until golden.
Add the grilled tofu, mushrooms, onion, and green onion to the pan.
Mix soy sauce, chili powder, minced garlic, sugar, and water to make the sauce.
Pour the sauce into the pan and simmer until slightly thickened.
When the sauce boils down, drizzle with sesame oil and sprinkle sesame seeds.