Slice the tofu into 1cm thick pieces.
Pat the tofu dry with a kitchen towel.
Heat cooking oil in a pan and pan-fry the tofu until golden brown on both sides.
Mix soy sauce, minced garlic, sesame oil, chopped green onion, chili powder, sugar, and water to make the marinade.
Evenly pour the marinade over the grilled tofu.
Cover the pan and steam the tofu over low heat for 3–5 minutes so the flavors soak in.