Cutting bok choy for wonton soup is relatively simple.  First, you'll want to wash the bok choy and pat it dry with a clean kitchen towel or paper towel.  Then, cut off both the root end and the leafy top, and discard them.  Cut each stalk in half lengthwise so that you have two long halves. Slice each half into thin strips, about 1/4 inch wide.  Finally, roughly chop the thin strips into small pieces. This will make it easier to stuff your wonton wrappers and get a nice texture in your soup when everything cooks together!