Pound the chicken breasts with a meat mallet until they are a uniform 1/2-inch thick.
Mix together the flour, garlic powder, oregano, salt, and black pepper in a shallow dish.
Coat the chicken breasts in the flour mixture, shaking off the excess flour, until the breasts are evenly coated.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook until golden brown and cooked through, about 4-5 minutes per side. Remove the chicken and transfer to a plate.
Reduce the heat to medium. Add the butter to the skillet and stir in the minced garlic. Cook for 1 minute until fragrant.
If using, add the white wine to the skillet and use a wooden spoon to scrape up any browned bits from the bottom of the pan. Cook for 1 minute.
Stir in the chicken broth and then the heavy cream. Stir and bring to a simmer.
Sprinkle in the Parmesan cheese and whisk until the cheese has melted into the sauce.
Return the chicken breasts to the skillet and turn to coat in the sauce.
Once the chicken is hot, remove from the heat and top with the chopped parsley. Serve warm.