01 - Place chicken breasts between sheets of parchment paper and gently pound with a meat mallet to an even ½-inch thickness.
02 - Combine flour, salt, and pepper in a shallow bowl. Dredge each chicken breast in the seasoned flour, shaking off any excess coating.
03 - Heat 2 tablespoons olive oil in a large skillet over medium-high heat. Sear chicken for 4 to 5 minutes per side until golden brown and cooked through. Transfer to a plate and tent loosely with foil.
04 - Add the remaining tablespoon of olive oil to the skillet. Sauté mushrooms for 4 to 5 minutes until deeply browned. Stir in 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. Let the liquid reduce by half, about 2 to 3 minutes.
06 - Add the chicken broth to the skillet and simmer for 3 to 4 minutes, allowing the flavors to meld together.
07 - Return the seared chicken to the skillet and spoon the mushroom sauce over the top. Simmer for 3 to 5 minutes until the chicken is heated through and the sauce has thickened slightly.
08 - Sprinkle with chopped fresh parsley and serve immediately while hot.