Preheat your oven to 325°F (165°C). Pat the chicken pieces completely dry with paper towels — this is essential for a good sear. Season generously on all sides with salt and pepper, then lightly dust each piece with flour, shaking off any excess.

In a large Dutch oven or heavy braiser, cook the bacon pieces over medium heat until the fat is rendered and the bacon is lightly golden, about 6-8 minutes. Remove the bacon with a slotted spoon and set aside, leaving the fat in the pot.

Increase heat to medium-high. Working in batches so as not to crowd the pan, sear the chicken pieces skin-side down in the bacon fat (adding 1 tbsp olive oil if needed) until deep golden brown, 5-6 minutes per side. Do not move the chicken — let it release naturally. Transfer seared chicken to a plate and set aside.

Reduce heat to medium. Add the pearl onions, carrots, and celery to the pot and cook, stirring occasionally, until lightly softened and beginning to color, about 4 minutes. Add the smashed garlic and cook 1 minute more until fragrant.

Add the tomato paste and stir to coat the vegetables. Cook for 2 minutes, stirring, until the tomato paste darkens slightly — this step adds significant depth of flavor.

Pour in the entire bottle of red wine, scraping up any browned bits from the bottom of the pot with a wooden spoon. Add the chicken stock. Tie the thyme sprigs, bay leaves, and parsley sprigs into a bundle with kitchen twine (bouquet garni) and nestle it into the pot.

Return the seared chicken and reserved bacon to the pot. The liquid should come about two-thirds of the way up the chicken; add more stock if needed. Bring to a gentle simmer.

Cover the Dutch oven with its lid and transfer to the preheated 325°F oven. Braise for 60-75 minutes, until the chicken is completely tender and pulling away from the bone. The internal temperature should reach at least 175°F for dark meat.

While the chicken braises, heat the remaining 1 tbsp olive oil in a skillet over medium-high heat. Sauté the mushrooms with a pinch of salt until golden brown, about 5-6 minutes. Set aside.

Remove the pot from the oven. Carefully transfer the chicken pieces to a plate and cover loosely with foil. Remove and discard the bouquet garni.

Place the Dutch oven over medium-high heat on the stovetop. Bring the braising liquid to a boil and cook, stirring occasionally, until the sauce has reduced and thickened enough to coat the back of a spoon, about 10-15 minutes.

Reduce heat to low. Stir in the butter until melted and glossy. Add the sautéed mushrooms. Taste and adjust seasoning with salt and pepper. Return the chicken to the pot and gently spoon the sauce over each piece to coat.

Serve immediately, garnished with fresh parsley and thyme leaves, over egg noodles, creamy mashed potatoes, or with crusty bread. Enjoy.