In a large skillet or large pot over medium-high heat, brown the chicken in the butter. Season with salt and pepper. Add the onion and garlic. Continue to cook for 2 minutes. Deglaze with the whisky. Add the broth and mushroom mixture, cream and mustard. Bring to a boil while stirring. Cover and simmer gently for 45 minutes. Flip the chicken pieces over and continue to cook, covered, for 15 minutes or until the chicken is cooked through.
