I think we have a winner! Googled it and this came up, which looks exactly like them:(Original post by onefour)
'Really chewy pasta' sounds more like rice cakes than water chestnuts. If so, they're usually boiled in soups until they soften though you can stir-fry them as well. I don't know what they are called in Chinese but they're called 'ddeok' (although the spelling varies) in Korean so you could search for recipes that way or at least confirm that's what your mystery ingredient is.
Will Oxford nullify my offer?