It's also one of those dishes with five billion variations, and I think I have a lot of them in my food library (even though it's a small library by my standards). As a result, this is the way I did it this time, but I've done it differently before and probably will again (I was out of dried porcini mushrooms this time, which is usually a must-have ingredient). My basic recipe comes from Mark Bittman's How to Cook Everything.
Take four bone-in skin-on chicken thighs, pat dry, roll in all-purpose flour seasoned with salt and cracked black pepper. Shake off the excess. Fry some chopped bacon (in this case, maple-honey bacon from the Pennsylvania Dutch Farmers Market, but any bacon will do). Remove the bacon from the pan and saute the chicken thighs in the bacon fat until brown. Remove the chicken from the pan, pour the remaining oil into a pot, then saute one chopped onion, two chopped portobello mushroom caps and two chopped garlic cloves in the oil. When the onion starts sweating, add a cup each of red wine and chicken stock, a good squirt of tomato paste, a bay leaf, chicken blood if you have it, the bacon and its juices, the chicken thighs and their juices, a couple of sprigs of fresh thyme and another shot of salt and cracked black pepper. Cover, turn the heat to medium and let simmer for a while.
After at least an hour, uncover the pot and turn the heat up to reduce the sauce. Coq au vin works well with crusty bread, noodles, rice or potatoes.
About that chicken blood: it's a traditional ingredient of coq au vin, in the vein (sorry) of using everything for the dish (which was originally a peasant stew intended to use up an old played-out rooster). But just do a search online and find plenty of argument about it. I don't go looking for chicken blood, but just taking the juices out of a chicken package (particularly a whole chicken intended for roasting) will involve some blood. I've made coq au vin with and without blood, and both are good, but it does make a difference. Coq au vin with blood has a unique blackish tint and an extra something to the flavor that is difficult to describe, but you know it when you taste it.