When many people first hear of the dish "chicken merlot", they often confuse it for coq au vin, a traditional French dish that braises chicken in wine. While it's true that chicken merlot is similar in that the two both include chicken and wine, that's where the similarities end. While coq au vin wouldn't be the dish it is without the inclusion of mushrooms, they're optional in chicken merlot, and I've decided not to include them in mine.
Chicken merlot also often includes tapioca to thicken it up; and again, I've chosen not to include it in mine. What I did include, and what you must include when making a proper chicken merlot is tomato of some kind. I chose tomato paste, but it varies between recipes. That tomato is important, especially when serving chicken merlot over buttered egg noodles, as it creates a delicious sauce for the entire plate.
Pro tip: If you want to add mushrooms to this dish, you can either saute them while the sauce is thickening, or throw them right into the bottom of the slow cooker along with the other veggies.