01 -
Place halved chicken breasts between sheets of parchment paper or plastic wrap on a cutting board. Using a meat mallet or rolling pin, pound each piece to an even, thin thickness.
02 -
In a zip-close bag, combine all-purpose flour, 1/2 teaspoon salt, garlic powder, and black pepper. Add chicken cutlets one at a time and shake to coat evenly, discarding excess flour afterwards.
03 -
Heat a large skillet over medium-high heat. Add olive oil and 1 tablespoon butter. When hot, add chicken cutlets in a single layer and cook 3 to 5 minutes per side, until golden brown and cooked through. Cook in batches as needed. Transfer seared chicken to a plate and keep warm.
04 -
To the same skillet, add remaining 2 tablespoons butter. Add sliced mushrooms and sauté over medium heat until browned, about 3 minutes. Add diced onion and minced garlic, season with remaining 1/2 teaspoon salt, and cook until onions are tender, about 3 minutes.
05 -
Pour in Marsala wine, scraping up browned bits from the pan bottom with a wooden spoon. Add chicken broth and heavy cream. Stir to combine, reduce heat, and simmer until sauce slightly thickens, about 7 minutes.
06 -
Return chicken cutlets and any juices to the sauce, gently heating through until hot. Garnish with chopped parsley and serve immediately.