Can of chicken. Or boiled chicken breast, cut up, if you want to avoid the canned stuff. It's cheaper, too.
Some mayo (or your favorite substitute. Or walnut oil.)
salt and pepper.
Walnuts (not crushed, but they probably should be halved at the very least)
Chop up the onion, celery, a bit of the bell pepper (this must be done very finely), and put it in a bowl with the mayo. Add a bit of salt and pepper, and a handful of cranberries. Stir. THen you are ready to make a sandwich or a wrap or whatever you want. Mmm.