Easy and delicious
This dish was delicious. I was just going to reheat some leftover chicken breasts with veggies, but I found this, and boy, am I glad! The sauce texture was delightful, not entirely smooth and creamy, but hardy. The flavour was bold (especially if you add enough fresh-ground pepper). Nothing boring about this dish (it could use more colour though for my liking).
I made a few substitutions based on available ingredients - broccoli for cauliflower, light mozzarella and marble cheeses in place of the Gruyere with the addition of some Parmesan, and salt-free beef broth in place of the wine. I also added zucchini for more vegetables. I could not be more pleased with the result.
To those who said the sauce didn't thicken up, cook it for longer over higher heat (make sure to keep stirring so it doesn't burn). The 1-minute suggestion to thicken the sauce is not even enough to bring the sauce to a boil. Make sure you bring it to a boil!!! and reduce heat when you reach the desired consistency. I cooked mine a bit too long and added more beef broth to thin it out - still fantastic.
I will definitely make this again and again and recommend it to anyone looking to give leftover chicken a bit of pizazz.