Sprinkle salt, pepper and onion powder over the chicken on both sides.
In a large skillet, heat one tablespoon of butter and the olive oil then add the chicken breasts and cook for 4-5 minutes on each side.
Take the chicken off the skillet, place them in a plate then set aside.
Making the creamy garlic mushroom sauce
In the same skillet, add one tablespoon of butter, garlic and mushrooms, cook for 3-4 minutes until the mushrooms become golden brown.
Add chicken stock, vinegar and heavy cream (slowly), stir then bring to a boil then reduce the heat and let the sauce simmer for about 3-4 minutes or until it slightly thickens.
Add the chicken in the creamy mixture and garnish with chopped parsley.
Notes
Add fresh herbs to this one-pan dish, such as thyme, rosemary or basil.
You can also add a pinch of red pepper flacks to make the dish a little spicy.