Prep the chicken- Start by seasoning the chicken cutlets with salt and pepper on both sides.
Cook the chicken- Heat 2 tablespoons of butter in a large pan over medium-high heat. Add the chicken and cook until golden brown on both sides, about 3-5 minutes per side. Remove the chicken from the pan and set aside.
Prepare the sauce- In the same pan, add the remaining butter, minced garlic, and finely chopped shallots. Sauté until the shallots become translucent. Add the sliced mushrooms and cook till they’re browned and softened.
Deglaze the pan- Pour the Marsala wine into the pan, using a wooden spoon to scrape any browned bits from the bottom of the pan. This process is known as deglazing and it adds a depth of flavor to the sauce.
Simmer- Allow the Marsala wine to simmer and reduce by half. This should take about 5-7 minutes.
Combine the chicken and sauce- Add the cooked chicken cutlets back into the pan, turning to coat them in the Marsala sauce. Let the chicken simmer in the sauce for a few more minutes to absorb the flavors.
Serve- Transfer the chicken to a serving dish. Pour the remaining sauce over the chicken and garnish with fresh herbs if you wish. Serve hot over pasta or mashed potatoes.