Put the greens in the base of a shallow bowl that will fit into a large steamer. (Alternatively, use a lidded wok: fill the base of the wok with water and put a heatproof trivet on the bottom to stand the bowl on so it’s above the water line). Place the tofu on top of the greens and thickly slice. Mix the rice wine, soy sauce and sugar with 2 tbsp water and pour over the tofu. Cover and steam for 5 mins or until the tofu is hot.
Heat the oil in a small pan, add the spring onion and ginger, sizzle for a min, then add the chilli flakes and a splash of sesame oil. When hot, pour carefully over the tofu. Serve with rice.