Slice the tofu into 1cm thick pieces.
Lightly sprinkle salt over the tofu and let it sit for 10 minutes.
Add cooking oil to a pan and pan-fry the tofu on both sides until golden brown.
In a bowl, mix soy sauce, water, chili powder, minced garlic, sugar, sesame oil, and pepper to make the sauce.
Pour the sauce over the grilled tofu and top with onion and green onion.
Cover with a lid and simmer on low heat for 10 minutes.