Although it is possible to buy pre-made packages in the Chinese grocery, the homemade version is much tastier.
Slightly sour with a mild mustardy bite, it has tender chewy leaves and crunchy pickled stems.
In our fridge there was always a jar of pickled Ham Choy, normally on the bottom shelf, pushed back behind the bottles and bags of other things, waiting to be retrieved and cooked.
Wash and clean the mustard leaves. Cut stems apart but leave the leaves intact.
Leave at room temperature for approximately 2 hours. Over this time the leaves will soften and wilt, rendering a lot of water. After the first hour or so, knead the softened leaves together to distribute the salt and press out the excess water. After two hours, drain and dispose of the water and extra salt. Do not rinse.
Fold leaves and pack into clean bottles
In a separate bowl, mix the solution of vinegar, water, sugar and cornstarch.
Pour into the bottles over the packed vegetable.
Use a weight in each bottle to submerge the leaves in the solution. It is important to totally submerge the greens with liquid.
Leave at room temperature to continue curing. Do not refrigerate. After 2 to 3 days the mustard will lose its bright green color and have the conventional dark green color of Ham Choy. At this time, the pickling is complete. Cover and seal the bottles and store in the refrigerator