My aunt brought this to every summer graduation party for 30 years. Three ingredients and it disappeared before the potato salad every single time.

This oven baked 3-ingredient chicken Lombardy is exactly the kind of dish my Aunt Carol brought to every graduation open house across the Midwest for three decades. It’s the pan that showed up right next to the potato salad and somehow vanished first, long before anyone thought about dessert. The beauty here is in the simplicity: chicken, mushrooms, and cheese, layered and baked until everything is golden, bubbling, and a little bit nostalgic. It’s not a classic Italian Lombardy dish so much as a potluck-era interpretation—built for busy home cooks, easy to transport in a casserole dish, and universally crowd-pleasing.

Serve this chicken hot right from the casserole dish with simple, familiar sides that can share buffet space: buttered egg noodles or mashed potatoes to catch the cheesy pan juices, a crisp green salad with a tangy vinaigrette to balance the richness, and something like steamed green beans or roasted broccoli for color and crunch. At parties, it holds well on a warm setting and pairs nicely with soft dinner rolls, a chilled white wine such as Pinot Grigio, or iced tea and lemonade for a classic Midwestern spread.

Servings: 6

2 pounds boneless, skinless chicken breasts (about 4–6 medium pieces), trimmed

Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch white ceramic or glass casserole dish so the chicken doesn’t stick and cleanup is easier.

Pat the chicken breasts dry with paper towels. If they are very thick, slice them horizontally into cutlets so they bake evenly and stay tender.

Arrange the chicken breasts in a single layer in the prepared casserole dish, nestling them close together but not overlapping too much. This helps them cook at the same rate and makes for a neat presentation.

Scatter the sliced mushrooms evenly over the top of the chicken, making sure every piece gets a generous layer. Press some mushrooms gently into the spaces between the pieces so they sit snugly and don’t dry out.

Sprinkle the shredded Italian blend cheese evenly over the mushrooms and chicken, covering the entire surface. Aim for a solid layer so you get that bubbly, golden top and the stretchy cheese pull when you serve.

Cover the dish tightly with foil and bake for 20 minutes. This covered time allows the chicken to cook through gently while the mushrooms release their juices and the cheese melts smoothly.

After 20 minutes, carefully remove the foil (watch for steam). Return the uncovered dish to the oven and bake for another 15–20 minutes, or until the cheese is deeply melted and starting to turn golden brown around the edges and the thickest piece of chicken reaches an internal temperature of 165°F (74°C).

For extra browning, move the dish to the upper third of the oven for the last 3–5 minutes, watching closely so the cheese doesn’t scorch. You’re aiming for a lightly blistered, golden top.

Remove the casserole from the oven and let it rest for 5–10 minutes before serving. This short rest helps the juices settle so the chicken stays moist and makes it easier to lift out neat portions with a wooden spoon or spatula, complete with that classic stretchy cheese pull.

If you’d like a bit more character while still keeping the three-ingredient spirit, choose a bolder Italian cheese blend (one that includes provolone, asiago, or fontina) for deeper flavor. You can also swap in smoked mozzarella for part of the cheese to give the dish a subtle, almost grilled note without adding extra ingredients. For mushrooms, cremini (baby bella) will give a more robust, earthy flavor than basic white button mushrooms. If you need to stretch the recipe for a larger crowd, slice the chicken into thinner cutlets, fan them slightly in the dish, and add an extra cup of cheese to ensure full coverage; increase baking time by 5–10 minutes as needed, checking doneness with a thermometer. To make ahead for a party, assemble the dish up to the point of baking, cover tightly, and refrigerate for up to 24 hours, then add 5–10 minutes to the covered baking time since it will be starting cold. For food safety, always keep raw chicken refrigerated until you’re ready to assemble, wash hands and any surfaces or utensils that touch raw poultry, and use a dedicated cutting board for meat if possible. Bake until the thickest part of each chicken breast reaches at least 165°F (74°C); don’t rely solely on color. Once baked, avoid leaving the dish at room temperature for more than 2 hours (or 1 hour if it’s a very warm day at an outdoor party). Leftovers should be cooled quickly, stored in shallow containers in the refrigerator, and eaten within 3–4 days, reheated thoroughly until steaming hot before serving.