Preheat the oven to 350 degrees F.
Coat the chicken breasts in the dressing mix.
Heat the oil in a large nonstick skillet over medium-high heat until very hot. Add the chicken and cook undisturbed until well browned, about 4 minutes. Turn the chicken, add the butter to the pan, and cook until the chicken is just golden brown on the reverse side, 3 minutes more. Transfer the chicken to a large baking dish.
To the skillet, add the mushrooms and a pinch of salt; cook, stirring occasionally, until golden brown, about 5 minutes. Spoon the mushrooms on top of the chicken.
In a medium saucepan combine the soup, cream cheese and wine. Stir over medium-high heat until well blended and heated through. Pour the sauce over the chicken and mushrooms.
Bake, uncovered, until the chicken is cooked through, 1 hour. Sprinkle with parsley and serve.