Step 1: Prepare the Chicken
Pat the chicken breasts dry with paper towels. If they’re particularly thick, pound them to an even thickness (about 3/4-inch) using a meat mallet. Season both sides with garlic powder, Italian seasoning, paprika, salt, and pepper.

Step 2: Sear the Chicken
Heat olive oil in a large skillet over medium-high heat. Once hot, add the chicken breasts and cook for 5-6 minutes per side until golden brown and nearly cooked through (internal temperature should reach about 155°F as they’ll continue cooking later). Transfer to a plate and cover loosely with foil.

Step 3: Sauté the Mushrooms
In the same skillet, melt the butter. Add the sliced mushrooms and cook undisturbed for 2 minutes, then stir and continue cooking for another 3-4 minutes until golden brown. Add the minced garlic and cook for 30 seconds until fragrant.

Step 4: Create the Sauce
Pour in the chicken broth, scraping up any browned bits from the bottom of the pan. Let it simmer for 2 minutes, then stir in the heavy cream and Dijon mustard. Bring to a gentle simmer and cook for 2-3 minutes until slightly thickened.

Step 5: Combine and Finish
Return the chicken to the skillet, nestling it into the creamy mushroom sauce. Sprinkle shredded Swiss cheese over each chicken breast. Cover the skillet with a lid or aluminum foil and cook on low heat for 3-5 minutes until the cheese is melted and the chicken reaches 165°F (74°C).

Step 6: Serve
Garnish with freshly chopped parsley and serve immediately.