Prep the Oven: Preheat your oven to 350°F (175°C). Lightly grease a baking dish or use foil trays for easy cleanup, just like in your photo.
Layer the Chicken: Place the chicken breasts in a single layer in the pan. If they are very thick, you can give them a quick pound to ensure even cooking.
The Secret Sauce: In a small bowl, whisk together the condensed cream of mushroom soup and the dry onion soup mix. Do not add water or milk—the juices from the chicken will thin the sauce perfectly as it bakes.
Cover and Bake: Spread the mixture evenly over the chicken. For the most tender results, cover the pan tightly with aluminum foil. Bake for 45 to 60 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
The Finishing Touch: If you want those mushrooms to look extra “golden” like the ones in your image, remove the foil for the last 10 minutes of baking.