Prepare the chicken: Pat the chicken pieces thoroughly dry with paper towels. This is crucial for achieving a good sear. Season generously on all sides with salt and freshly ground black pepper.

Cook the bacon: In a large, heavy-bottomed pot or Dutch oven (at least 5-6 quart capacity), cook the diced bacon over medium heat until crisp and rendered. This should take about 8-10 minutes. Using a slotted spoon, remove the bacon to a plate lined with paper towels, leaving the rendered fat in the pot.

Sear the chicken: Increase the heat to medium-high. Add 2 tablespoons (30ml) of olive oil to the pot with the bacon fat. Working in batches to avoid overcrowding the pot, sear the chicken pieces on all sides until deeply golden brown. This browning develops crucial flavor. Remove the seared chicken to a separate plate and set aside.

Sauté the aromatics: Reduce the heat to medium. Add the chopped yellow onions and sliced carrots to the pot. Cook, stirring occasionally, until the onions are softened and lightly browned, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant, being careful not to burn it.

Make the roux: Sprinkle the flour over the vegetables in the pot. Stir well and cook for 1-2 minutes, allowing the flour to coat the vegetables and cook out its raw taste. This mixture will help thicken the sauce.

Deglaze with wine: Pour in the 750ml (3 cups) of red wine. Scrape the bottom of the pot with a wooden spoon to loosen any browned bits (fond) stuck to the bottom. Bring the wine to a simmer and let it cook for 2-3 minutes, allowing some of the alcohol to evaporate and the sauce to slightly reduce.

Add liquids and herbs: Pour in the 500ml (2 cups) of chicken broth. Stir in the 1 tablespoon (15ml) of tomato paste. Add the fresh thyme sprigs and the bay leaf. Bring the mixture to a gentle simmer.

Return chicken and braise: Carefully return the seared chicken pieces and any accumulated juices back into the pot, nestling them into the liquid. The liquid should come about halfway up the sides of the chicken. Ensure the pot is large enough to hold everything comfortably without overcrowding.

Simmer and braise: Bring the liquid back to a gentle simmer, then reduce the heat to low. Cover the pot tightly with a lid. Let the coq au vin braise gently for 45-60 minutes, or until the chicken is very tender and cooked through. Stir occasionally to prevent sticking.

Prepare the mushrooms and pearl onions: While the chicken is braising, melt 2 tablespoons (30g) of butter in a separate skillet over medium-high heat. Add the quartered or halved mushrooms and cook, stirring occasionally, until they are nicely browned and have released their liquid, about 5-7 minutes. If using pearl onions, add them to the skillet with the mushrooms during the last 5 minutes of cooking, or until they are tender and lightly caramelized.

Remove chicken and finish sauce: Once the chicken is tender, carefully remove the chicken pieces from the pot and set them aside on a warm plate. Discard the thyme sprigs and bay leaf. If the sauce seems too thin, increase the heat to medium-high and let it simmer uncovered for 5-10 minutes, stirring occasionally, until it has thickened to your desired consistency. Taste and adjust seasoning with salt and pepper as needed.

Combine and serve: Return the chicken pieces to the pot with the thickened sauce. Add the cooked bacon, sautéed mushrooms, and pearl onions (if using) to the pot. Gently stir to combine everything and allow it to heat through for about 5 minutes.

Garnish and serve: Ladle the Coq au Vin into shallow bowls or onto plates. Garnish generously with fresh chopped parsley. Serve hot, traditionally with crusty bread for soaking up the delicious sauce, mashed potatoes, or egg noodles.