Preheat oven to 350°F (175°C). Season chicken with salt and pepper, then dredge in flour.
In a large skillet, heat oil over medium heat. Sear chicken until golden brown on both sides, about 3–4 minutes per side. Transfer to a 9×13-inch baking dish.
In the same skillet, melt butter. Add mushrooms and garlic and sauté until mushrooms are browned and moisture has evaporated.
Deglaze the pan with sherry, scraping up any browned bits. Let simmer for 2 minutes.
Stir in the cream of mushroom soup and heat through.
Pour the sauce over the chicken in the baking dish and top each piece with a slice of Muenster cheese.
Cover with foil and bake for 25 minutes. Uncover and broil for 2–3 minutes until cheese is bubbly and lightly browned.
Garnish with parsley and serve warm.
Notes
Can substitute Muenster cheese with Swiss or mozzarella.
Use low-sodium soup to control salt content.
Dry white wine can replace sherry if unavailable.
For extra flavor, add a splash of Worcestershire sauce to the mushroom mixture.
Pairs well with rice, mashed potatoes, or egg noodles.