Grill the chicken on medium-high heat, grill about 10-15 minutes on each side. These can be seasoned per your preference. They need to be heated up until 165* internal temperature.
In a medium-sized skillet, spray it with cooking spray then add in the olive oil.
Warm to medium-high heat, then add in the onion, mushrooms, and parsley.
Saute this for about 2-5 minutes, then add in the chicken broth and wine.
Let this cook for about 5-10 minutes until cooked down to about 1/2 a cup.
Remove from heat, then whisk or stir in the butter, cheese, and flour.
Add the garlic salt to taste, we prefer about a teaspoon.