Sprinkle the chicken cutlets with seasoned salt on both sides. Lightly dip in the flour. Set on a plate.
In a large skillet, heat the olive oil on medium high heat. Add the chicken and cook for 5 minutes on each side, until chicken is no longer pink. If all the chicken does not fit, cook in two batches. You might need to add another tablespoon of olive oil to the pan for the second batch. Transfer the chicken to a plate and keep warm with a piece of foil on top.
Add the wine to the pan. Deglaze the pot by making sure to stir up all the brown bits from the bottom. When the liquid starts to simmer, add the mushrooms and cook for 5 minutes or until they are softened. Add the butter to the sauce and stir well until melted and sauce is simmering.
Return all the chicken to the pan. Pour a bit of the sauce over the chicken, reduce heat and cover. It is okay if the pan is a little crowded. Cook for 5 minutes or until juices run clear and chicken is cooked through. It should be at 165 degrees if using an instant read thermometer.
Sprinkle chicken with parsley. Transfer chicken to a serving plate, spooning sauce and mushrooms on top. Season with salt and pepper to taste.
Chicken broth can be substituted for white wine if necessary. Also, if you like a little more sauce with your chicken you can add an extra 1/2 cup chicken broth when adding the wine.