My mother-in-law makes this for Sunday lunch, and the crispy topping is absolutely addicting! Only 4 ingredients.

This oven baked 4-ingredients French onion chicken bake is the kind of no-fuss comfort food my Midwestern mother-in-law loves to put on the table for Sunday lunch. It leans on the classic flavors of French onion soup—caramelized onion richness and nutty Swiss cheese—but simplifies everything into one casserole dish. A blanket of melty Swiss over tender chicken, finished with a layer of crispy fried onions, gives you that deeply savory, slightly sweet onion flavor with a satisfyingly crunchy topping that everyone fights over. It’s practical, affordable, and uses just four ingredients you can keep on hand for an easy, crowd-pleasing meal.

Serve this French onion chicken with something that can soak up the flavorful juices in the bottom of the dish—mashed potatoes, buttered egg noodles, or a simple rice pilaf all work beautifully. A crisp green salad with a tangy vinaigrette helps cut through the richness, and steamed green beans or roasted broccoli make an easy vegetable side. If you’re serving a larger group for Sunday lunch, add a loaf of crusty bread and a light dessert, like fruit or sorbet, to round out the meal without much extra effort.

Servings: 4

4 boneless, skinless chicken breasts (about 2 pounds total)

Preheat your oven to 375°F (190°C). Lightly grease a rectangular glass casserole dish (about 9x13 inches) with a bit of oil or nonstick spray so the chicken doesn’t stick.

Pat the chicken breasts dry with paper towels and trim any excess fat. Arrange the chicken in a single layer in the prepared casserole dish, leaving a little space between each piece so they cook evenly.

Pour the condensed French onion soup evenly over and around the chicken breasts, making sure each piece is coated. You don’t need to add water or milk—the soup should be used straight from the can for maximum flavor.

Cover the casserole dish tightly with foil and bake for 25 to 30 minutes, or until the chicken is just cooked through and reaches an internal temperature of 165°F (74°C). The soup will create a flavorful, onion-rich sauce around the chicken.

Carefully remove the foil. Lay the slices of Swiss cheese over the top of the hot chicken breasts, overlapping slightly as needed so each piece is fully covered. Spoon a little of the oniony pan juices over the cheese if you like a softer melt.

Sprinkle the crispy fried onions evenly over the cheese, building a generous, even layer that will form the golden, crunchy topping. Try to cover as much of the cheese as possible so the onions toast rather than burn.

Return the uncovered casserole dish to the oven and bake for another 10 to 15 minutes, or until the cheese is melted, the fried onions are deep golden brown and crisp, and the sauce is bubbling around the edges.

Let the chicken rest for 5 minutes out of the oven so the juices settle slightly. Serve each chicken breast topped with some of the crispy onion-cheese layer, spooning a bit of the French onion sauce from the bottom of the dish over or alongside each portion.

For a little extra depth, you can season the chicken lightly with black pepper and dried thyme before adding the soup, though the recipe is designed to work with just the four main ingredients. If you prefer darker, nuttier flavor, swap in Gruyère for the Swiss cheese, keeping the slices fairly thin so they melt nicely. For smaller appetites or buffet-style serving, use chicken cutlets instead of full breasts and reduce the initial covered bake time by 5 to 10 minutes, checking for doneness early. To make the dish slightly lighter, choose reduced-sodium condensed French onion soup and use a modest amount of cheese, but keep the crispy onions generous so you don’t lose that signature crunch. If you like a more pronounced onion flavor, stir a spoonful of the crispy fried onions into the soup before baking, then still finish with a full layer on top. Leftovers reheat well in a moderate oven (around 325°F/165°C) until warmed through and re-crisped on top; avoid the microwave if you want to keep the topping crunchy.