Preheat the oven to 350F.
On the stovetop, heat a Dutch oven or braiser to medium heat and add bacon. Cook until crispy, 8-10 minutes. Remove bacon and drain off excess fat.
Pat dry the chicken and season with salt. Working in batches, brown the chicken on each side for approximately five minutes. Set aside.
Add the garlic, onions, thyme, bay leaf, tomato paste, and bacon to the pot. Stir and cook until fragrant, approximately 1 minute.
Return the chicken to the pot. Add the carrots and pour the wine and stock over everything. Bring to a simmer, cover, and then place in the oven. Cook for 30 minutes.
Remove from the oven. Combine melted butter and flour in a small dish and slowly whisky in 1/4 cup of the liquid from the pot. Gently pour over the whole dish.
Add mushrooms. Cover and cook over medium heat for 10 minutes or until chicken reads 165F on a meat thermometer.