01 - Place chicken breasts between sheets of parchment paper and gently pound to an even ½-inch thickness using a meat mallet.
02 - In a shallow bowl, combine the flour, salt, and black pepper. Dredge each chicken breast lightly in the seasoned flour, shaking off any excess.
03 - Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook for 4 to 5 minutes per side until golden brown and cooked through. Transfer to a plate and cover loosely with foil.
04 - Add the remaining 1 tablespoon of olive oil to the skillet. Sauté the sliced mushrooms for 4 to 5 minutes until deeply browned. Add the minced garlic and cook for 30 seconds until fragrant.
05 - Pour in the Marsala wine, scraping up any browned bits from the bottom of the pan. Cook for 2 to 3 minutes until the liquid has reduced by half.
06 - Add the chicken broth to the skillet and bring to a simmer. Cook for 3 to 4 minutes to allow the flavors to meld together.
07 - Return the chicken breasts to the skillet, spooning the mushroom sauce over the top. Simmer for 3 to 5 minutes until the chicken is heated through and the sauce has thickened slightly. Garnish with fresh chopped parsley and serve hot.