If you're like me, then you'll never have any leftovers... I call it my "eating disorder" (not trying to be disrespectful to those who actually have issues, but I simply can NOT stop myself from eating ALL OF THE FOODS. My full-response does kick-in eventually, but generally requires eating more then enough food than any normal, active adult should eat in a week.
So you could make this from leftovers... I can't. There are never any leftovers.
roasted chicken (breast, thighs, whatever you've got from the shop-bought BBQ chicken you purchased). I confess I buy them all the time. Our shop has lovely free-range, hormone and antibiotic free birds that actually get to run around and live a long-ish (for a food-chicken) life. The shop even seasons and roasts the bird for $12.99. If I bought such a bird (in uncooked form) I would require 3 hours of kitchen labour and the organic, free-range birds cost $20+!
So back to the ingredients:
fresh bread (I like egg-bread with poppy-seed crust)
swiss or jarlesberg cheese
oregano (a few sprigs of fresh or a few tsp of dried)
2-6 strips of bacon cut into lardons and browned in a skillet (cooled)
mayonnaise (fresh if possible... shop-bought is fine in a pinch)
coarsely ground black-pepper
some finely chopped celery
some finely chopped red bell pepper
cherry tomatoes (in 1/2s or 1/4s)
a small portion of dried cranberries
(again apologies for the lack of specific quantities, but it all depends on how much chicken you have and how many sandwiches you're trying to make)
1. coarsely chop your chicken leftovers. A bit of skin is fine
2. put your chopped chicken in a large mixing bowl
3. add bacon, oregano, pepper, celery, bell pepper, cranberries, and toss with your hands
4. add mayo to taste. Err on the too-little side. You're not making mayonnaise salad.
5. serve on fresh (or toasted) bread with thin slices of cheese and lettuce.
No picture available... the food got eaten before cameras came out.
Unless you salt everything to death, there should be no need for added salt. The BBQ chicken should be seasoned as well as the bacon. (Plus there's already plenty of salt in cheese, and shop-bought mayo.)
If you use a freshly roasted chicken that's still warm you don't need to cool it... It's even more awesome when it's warm. However this will DRAMATICALLY reduce any shelf-life if you can't eat all you make. As in, don't even bother putting the extras in the fridge. Just put it in the bin if you can't eat it within an hour.