Chicken in Mustard

Preheat the oven to 350 degrees F. Rinse and dry the chicken thighs and season with salt and pepper. Heat 1 tablespoon olive oil in a Dutch oven over medium-high heat. Brown the thighs on both sides, working in batches if needed. Remove the chicken and set aside. Add the remaining 1 tablespoon olive oil to the Dutch oven and cook the onions until soft, about 5 minutes. Add the mushrooms and continue to cook until the mushrooms have softened, 3 to 5 minutes. Stir in the garlic and cook until fragrant, about 2 minutes. Add the tomatoes and flour and cook, stirring, to remove the raw flour flavor, about 3 minutes. Stir in the tarragon. Turn up the heat and deglaze the pan with the white wine, allowing to bubble for a minute or two. Return the chicken to the Dutch oven. Add enough chicken stock to reach halfway up the sides of the chicken. Cover, place in the oven, and braise for 45 minutes, removing the lid halfway through. When finished, remove the chicken from the Dutch oven and set aside. Add the mustard and sour cream and whisk to blend well. Return the chicken to the pan and allow the flavors to meld before serving, about 5 minutes. Serving suggestion: Serve over Super Buttered Noodles.