Prepare the green onions by cutting them diagonally. Separate the white parts from the green parts. Use a spoon to cut the firm tofu into bite-sized pieces.
In a small bowl, mix soy sauce, dark soy sauce, oyster sauce, sugar, cornstarch, and water.
Heat a nonstick pan over medium heat. Add neutral oil. Add the tofu and pan-fry until both sides are golden, about 3-4 minutes per side.
Make space in the pan and add the white parts of the green onion. Stir-fry for 1 minute until fragrant.
Stir the sauce again before adding it to the pan, as the cornstarch may settle at the bottom. Pour in the sauce, cover and simmer for 2–3 minutes, until it becomes thick and glossy.
Toss in the green parts of the green onion. Optional to add red chilies. Serve hot with rice.
