Marinate chicken. Cut the chicken legs in half and place them in a container. In a bowl, combine the wine, parsley sprigs, thyme sprigs, and bay leaf. Pour over the chicken, cover, and refrigerate overnight.Heat a heavy saucepan with a little oil. Add the bacon and cook until crisp, about 10 minutes. Transfer to a paper towel–lined plate to drain.Brown the chicken. Season with salt and pepper. Brown in batches, turning once, about 10 minutes per batch. Transfer to a plate.Cook the vegetables. Discard all but 2 tablespoons of fat from the pan. Add the mushrooms and cook until lightly browned, stirring occasionally. Add the shallots and cook for 2 minutes. Transfer to a bowl.Prepare the sauce. Melt the butter in the pan. Add the garlic, tomato paste, and flour; cook, stirring constantly, for 1 minute. Whisk in the reduced wine and broth, then bring to a simmer.Braise the chicken. Add the bacon, chicken, mushroom mixture, carrots, thyme, and bay leaf. Cover and cook in the oven at 160 °C until the chicken is fork-tender, about 1.5 hours.Finish and serve. Transfer the chicken to a plate and skim excess fat from the sauce. Discard the herbs. Adjust seasoning with salt and pepper. Return the chicken to the pan, garnish with chopped parsley, and serve with mashed potatoes.