Step 1

Look for cutlets that are between 1/4" and 1/2" thick.

Step 2

Pat cutlets dry with paper towels and season with salt and pepper. Dredge cutlets in flour to coat and shake to remove excess. Heat 1 tablespoon oil in large nonstick skillet over high heat until just smoking. Add 4 cutlets and cook until golden brown, 2 to 2 1/2 minutes on each side. Transfer to large plate and cover with aluminum foil. Repeat with remaining oil and cutlets.

Step 3

Heat 1 tablespoon butter in empty skillet over medium-high heat until foaming. Cook onion and mushrooms until browned, about 5 minutes. Add garlic and cook until fragrant, about 30 seconds. Transfer mushroom mixture to medium bowl and cover with foil.

Step 4

Add Marsala and broth to empty skillet, bring to boil over high heat, and cook until reduced to 1/2 cup, about 5 minutes. Reduce heat to medium-low, return chicken and accumulated juices to skillet, and turn chicken to heat through, about 1 minute. Transfer chicken to serving platter. Off heat, whisk in remaining 2 tablespoons butter, lemon juice, parsley, and mushroom mixture. Pour sauce over chicken. Serve.