Preheat a cast iron braiser over medium-high heat. Drop in your diced bacon. Saute until browned. Once browned, remove your bacon with a slotted spoon and set aside.
Reduce your heat to medium. Place your seasoned chicken (in batches), skin down, into the pan, and place the lid on. The skin should take about 5 minutes to brown.
Carefully try and lift your chicken using tongs. If it is resisting, it is not ready to flip. Once the skin is sufficiently browned, you will be able to lift your chicken with ease, without ripping the skin. Brown both sides - then remove from the braiser and allow to rest.
Add your celery, carrot, onion, and some salt and pepper to the braiser and saute in the juices. After 8-10 minutes, when your onions are translucent, add in your garlic and a healthy splash of brandy. Pour in one half of a bottle of red wine, scrapping at the bottom of your pan.
Add chicken broth.
Add your chicken, bacon, rosemary, and thyme. Reduce heat to medium low, and allow to simmer for 45 minutes.
Add your diced mushrooms to a pan with 1 tsbp butter. Saute until cooked. Add to your Coq Au Vin.
A tip from Ina Garten: Mix 1 tbsp of warm butter with 1 tbsp of flour. Add to your Coq Au Vin. Allow to simmer for approximately 10 minutes.
Taste and season with additional salt and pepper if required.