Step 1: Prepare the Chicken

1. Place each chicken breast between two sheets of plastic wrap and pound with a meat mallet until about 1/2 inch thick. This ensures even cooking.
2. In a shallow dish, mix the flour, garlic powder, onion powder, paprika, salt, and black pepper. Dredge the chicken breasts in the seasoned flour, shaking off any excess.

Step 2: Sear the Chicken

1. Heat the olive oil and 2 tablespoons of butter in a large skillet over medium-high heat.
2. Add the chicken breasts to the skillet and cook for 4–5 minutes per side, or until golden brown and cooked through (internal temperature of 165°F).
3. Remove the chicken from the skillet and set aside on a plate. Cover loosely with foil to keep warm.

Step 3: Sauté the Mushrooms

1. In the same skillet, add the sliced mushrooms and cook for 5–6 minutes, stirring occasionally, until softened and golden brown.
2. Add the minced garlic and cook for an additional 1–2 minutes, or until fragrant.

Step 4: Make the Marsala Sauce

1. Pour the Marsala wine into the skillet, scraping the bottom with a wooden spoon to deglaze and incorporate the browned bits for extra flavor.
2. Simmer for 2–3 minutes, allowing the wine to reduce slightly.
3. Stir in the chicken broth and heavy cream. Simmer for 5–7 minutes, or until the sauce thickens slightly. If a thicker sauce is desired, stir in the cornstarch slurry and simmer for another 1–2 minutes.

Step 5: Combine and Serve

1. Return the chicken breasts to the skillet, spooning the sauce over them. Simmer for 2–3 minutes to reheat the chicken and allow it to absorb the flavors.
2. Remove from heat and stir in the remaining 2 tablespoons of butter for added richness.
3. Garnish with freshly chopped parsley and serve hot.