Begin by patting your chicken breasts dry with paper towels. Season both sides generously with salt and pepper. This step is crucial to ensure a flavorful crust when searing.
Heat 2 tablespoons of olive oil in your skillet over medium-high heat. Once shimmering, add the chicken breasts. Cook for about 5-6 minutes on each side, until golden brown and cooked through. Remove the chicken from the pan and set it aside on a plate.
In the same skillet, add the sliced mushrooms. Sauté for about 4-5 minutes until they release their moisture and start to brown. Add the minced garlic and dried thyme; cook for another minute until fragrant.
Pour in 1 cup of chicken broth and 1 tablespoon of balsamic vinegar. Stir well, scraping the bottom of the pan to lift any flavorful bits. Let the sauce simmer for about 5 minutes, allowing it to reduce slightly and thicken.
Place the cooked chicken breasts back into the skillet, spooning some sauce over them. Let everything simmer together for 2-3 minutes to marry the flavors.
Sprinkle chopped fresh parsley over the top just before serving for a burst of color and freshness. This Chicken Marsala with Mushrooms (Skillet) pairs wonderfully with pasta or a side of steamed vegetables.