Heat oven to 350 (180C). Heat the olive oil in the Dutch oven on the stovetop over a medium to high heat. Add the sliced bacon and cook for 3-4 minutes, add the onion and cook for a few more minutes until soft.
Add the free-range chicken pieces and cook whilst stirring until browned. Add the mushrooms and cook for another 2 minutes. Season with salt and pepper. Pour over the 2 cups of red wine and chicken stock. Add the thyme and brown sugar, stir. Place the lid on the Dutch oven and place it inside the heated oven for 40 minutes.
Towards the end of the cooking time heat the butter in a small saucepan over a low to medium heat. When the butter has melted, add the flour and cook for a few minutes whilst stirring until a paste has formed. When the cooking time is up remove the Dutch oven from the oven. Remove the lid and add the butter and flour mix. Stir it constantly into the Coq Au Vin with a wooden spoon for a good 2-3 minutes until it has dissolved and the sauce has started to thicken. Allow to stand for at least 5 minutes before serving.