Cut tofu, onion, and green onion into bite-sized pieces.
Add perilla oil to a pan and sauté the onion and green onion.
Add tofu and grill both sides until golden brown.
Add mushrooms and minced garlic and stir-fry.
Season with soy sauce, salt, and pepper.
Add perilla powder and water, then simmer.
Top everything over rice and finish with chives and sesame seeds.