Heat the cooking oil and fry the tofu cubes until lightly browned. Scoop out and transfer to a plate.
Pour off the oil from the pan. The remaining oil that coats the bottom should be enough to cook the onion leaves in.
Reheat the pan. Cook the scallions for about 30 seconds and push to one side.
Pour in the oyster sauce, hoisin sauce, chili-garlic sauce and light soy sauce. Stir.
Add the tofu cubes to the pan. Toss with the green onions and cook for another 30 seconds or just until heated through.
Off the heat, squeeze in the lemon juice and toss a few more times. Serve the silken tofu with four sauces hot. With rice or by itself.