Chow Chai is a Foochow preserved vegetable, which has a signature sourish taste. It is used to cooked the Famous Chow Chai Mee Fern with Fish or Prawns. It can also be used to cook Chow Chai Soup. I am salivating now as I am writing.
You can hardly find Chow Chai outside Sarawak in Malaysia. Chow Chai had moved around through Foochow migrants to other parts of Malaysia. Still the best Chow Chai can be found in Sibu, where the Foochows actually dominates. So if you are overseas where this is not available, you may consider making it yourself.
Grand Aunt (Yi Po) had learned this from Great Grandma. And I was lucky Yi Po was in Kuching over the weekend. In theory, Chow Chai is made with the fermented leftovers of Foochow Red Wine. These leftovers are called Ang Chow, which is basically Red Rice and Glutinous Rice.
Sun dry the kua chai for a day or so. No need very dry as Chow Chai has no added water. Rub generously with Ang Chow and salt into mustards (kua chai). Stuff them tightly into a clean glass bowl and cover with tight lid for a week or so. Check to see if the mustards had fully fermented. If not leave it for another few days. Great Grandma used to stuff it tightly in clay urns and flip upside down on a bowl of water.
The hard part is to find Ang Chow. If you know someone who makes Foochow Red Wine, try getting some from them. If not, you can actually buy them in Sibu or at Kuching Tabuan Jaya Market at the Foochow stall selling toufu. Ang Chow can be used to cook Foochow Ang Chow Duck or Meat.
This is the theory only. I actually wanted to try making Foochow Red Wine first before doing the Chow Chai. (Greg: Nee is nuts) So once I have the photos, will blog it for those away from home.