Shan pickled mustard greens

Step 1: Wash 2 ¼ lb Chinese mustard greens (gai choy) and leave them spread out on racks in a sunny, airy spot for 4–6 hours, or overnight indoors, until the leaves are limp and the stems bend without snapping.

Step 2: Cut the greens into 5 cm pieces, stems split lengthways if thick. Rub them firmly with two-thirds of the ¾ oz fine sea salt for 3–4 minutes, until they soften, darken and release some juice.

Step 3: Put 7 oz uncooked white rice in a bowl, pour in 4 ¼ cups cool water and swish with your hand for 1 minute, until the water turns milky. Strain the water into a jug and keep the rice for another meal.

Step 4: Stir the rest of the ⅓ oz fine sea salt and 1 tbsp cooked rice into the rice water until the salt dissolves.

Step 5: Pack the greens tightly into a scrupulously clean 2-litre jar, layering in 4 garlic cloves and 3 dried red chillies as you go and pressing down hard.

Step 6: Pour over the rice water and any juice from the bowl until the greens are covered by at least 2 cm. Weigh them down with a small clean plate or a water-filled zip bag.

Step 7: Cover loosely with a lid or cloth and leave at cool room temperature for 3–5 days, pressing the greens down once a day. It is ready when the leaves turn yellow-green and taste pleasantly sour.

Step 8: A thin white film on the surface is harmless and can be skimmed off, but throw the batch away if you see fuzzy coloured mould, the greens turn slimy or it smells rotten rather than sour.

Step 9: Once sour enough, close the lid and keep in the fridge, greens under the brine, for up to 3 weeks. Squeeze out and chop before serving.