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 pepper. Dredge each chicken breast 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 and cook for 4–5 minutes per side until golden brown and cooked through. Transfer to a plate and cover loosely with foil.
04 - Add the remaining tablespoon of olive oil to the skillet. Sauté the sliced mushrooms for 4–5 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. Let the wine reduce by half, about 2–3 minutes.
06 - Add the chicken broth to the skillet and simmer for 3–4 minutes, allowing the flavors to meld and the sauce to begin reducing.
07 - Return the chicken to the skillet, spooning the mushroom sauce over the top. Simmer for 3–5 minutes until the chicken is heated through and the sauce has thickened slightly.
08 - Sprinkle with chopped fresh parsley and serve hot.