I probably did not see this in time, but there are a few options:
There are pre-packaged vegetarian chicken products in most (US) grocery stores. Some even have the fake chicken strips, which could be a good replacement. If fake meat isn't the option, instead of just going for tofu, try a spaghetti squash innards that replicate pasta, but will still flow with the other squashes and flavorings. If they are pescatarians, try using a white fish instead of chicken, but it will cook quicker.
Also, try substituting potatos in place of the chicken?
A couple on the market:http://www.morningstarfarms.com/morningstar-farms-meal-starters-chikn-strips.htmlhttp://www.lightlife.com/product_detail.jsp?p=smartstripschickn
Oooo...if you can find them, lightlife makes cuttlets and tenders also. (I have not tried these. Their hotdogs are pretty good. I usually use Morningstar products as they are the easiest, and cheapest, to find for me.)http://www.lightlife.com/strips-tenders.jsp
Now everyone knows a little more about veggie "meat". You're welcome.