Drain, dry then cut the tofu into 2 cm cubes.
Finely chop the garlic, ginger and chilli. Thinly slice the leek (including most of the green part).
Heat the groundnut oil in a wok. When it starts smoking, add the ginger, chilli and garlic and stir-fry for a minute. Add the beansprouts and the leek, then stir-fry for 3 minutes.
Add the soy sauce, rice wine and half of the sesame seeds. Stir-fry for a minute, then turn down the heat steam for a couple of minutes, under a lid, until the beansprouts have just wilted.
Stir in a drop of sesame oil and the coriander leaves, then transfer to a plate and keep warm, leaving the cooking jus in the wok.
Add some sesame oil to the wok, then turn up the heat and quickly stir-fry the tofu until golden on all sides. Add the sesame seeds, stir-fry for a few seconds, then move them to a plate.
Serve the bean sprouts with the tofu on top, garnished with sesame seeds and coriander leaves.