Chinese pickled mustard greens

Wash the greens thoroughly, rinsing between the leaves; discard the ends and cut each in half (rapini needs no cutting).

Dry on a rack: in the sun for 8 hours, or under a ceiling fan on high, or in a dehydrator at 95 F for 6 hours; halve the time for rapini.

Bring a pot of water to a boil and blanch the jars, lids and glass weights for 20 seconds; no need to dry them.

The greens are ready when the leaves are dry and wilted and the stems slightly bendable. Weigh them.

Weigh salt at 7% of the dried vegetable weight and rub it into the greens in a deep container, opening the leaves to salt between them, about 10 minutes, until the surface turns moist; this is the key to a crunchy pickle.

Roll up the leaves and pack into the jars, splitting greens and salt evenly; scrape in the salt left in the bowl so the ratio holds.

Fill the jars with distilled water, or boiled and fully cooled tap water; press the greens below the liquid with glass weights, and keep unwashed utensils out.

Ferment at room temperature for 15 days over a tray, optionally loosening the lid every two to three days to release gas so the brine does not overflow; the colour turns from green to brown.