Water spinach (rau muống in Vietnamese, ong choy in Cantonese) is a super popular green vegetable in Southeast Asia and Southern China, where it grows literally like a weed. The tender leaves and tops are boiled and stir-fried. The tougher, hollow stems (about 1/4 inch wide) are resourcefully split so that they're easier to chew.
In the Vietnamese kitchen, the shreds of stems are soaked in water until curly and crunchy. There's just a slight grassy flavor in the stems, which are enjoyed mostly for their nutritional value and texture. Typically, the shreds are lightly dressed with a vinaigrette for a salad or set out as a noodle soup garnish for guests who want to add extra crunch and fiber to their meal. (Eating too much of the stems, however, may lead to constipation.) Indeed, there's little waste when you're feeding lots of people.
A knife is traditionally used to split the stems, but the modern water spinach splitter (dao chẻ rau muống, literally “knife for splitting water spinach”) works much better and saves time. Blogger Jaden of Steamy Kitchen asked about this handy little tool and prompted this posting.

What is it and how does it work?
Dao chẻ rau muống (pronounced “zow chey rau moong”) is a thin metal rod attached to a round plastic top that contains a set of sharp blades arranged like wheel spokes. The entire tool measures about 10 inches long.
To use the splitter, first remove the tender leaves and tops and use them for stir-frying with garlic, etc. Aim for stems that are about 1/4 inch wide. Soak the stems first in water for about 5 minutes to firm them up and make them easier to split.
When you're ready, slide the splitter into a stem and then push
the stem through the blades until about 4 inches of split stem protrudes. Then grab the split portion and pull on it to drag the remaining stem portion through
the blades. If my description confuses, look on the back of the cute packaging for
instructions, such as the ones to the right.
Deposit the shreds in another bowl of cold water and let them soak for 10 to 15 minutes to curl. Drain well before using. The stems may be kept in a zip-top bag and refrigerated for up to 3 days.
If you're old school, you'll notice that using the tool gives you super tight, curly, kinky pieces . The traditional knife method yield results that are more like scallion greens that you'd leave to curl in water for decor. With the splitter, you get a mound of tangly corkscrews that could probably be glued together into a green wig. (Sorry I don't have a photo of the curls.) It's hard to eat the shreds that way or detangle them at the table. Avoid the super kinky by simply cutting the split lengths shorter before soaking.
Where can you buy one?
A water spinach splitter costs a pittance -- a few dollars at most. Ask a cashier at a Vietnamese market to direct you to the aisle where you will
find the handy gadget. The cashier often has the gadget nearby or tells someone
to get one for you. At an Asian
houseware or cookware store, like MV Trading Company or Kamei in the San
Francisco/Bay Area, the splitter hangs on the wall display of all gadgets that
includes peelers, thermometers, scissors, etc. When in doubt, ask!
Note: If you're hooked on water spinach, see the water spinach history posting on Vietworldkitchen.com.









