Cut the tofu into 1cm cubes.
Finely chop the onion and green onion.
Heat oil in a pan and grill the tofu pieces until golden brown on all sides.
Transfer the grilled tofu to a plate and set aside.
Sauté minced garlic and green onion in the pan.
Add onion and canned tuna, stir-fry together.
Add the tofu back in, then stir-fry with soy sauce, red chili powder, and sugar.
Finish with sesame oil and sprinkle with sesame seeds.