This oven baked 4-ingredient chicken Wellington casserole is one of those comforting back-pocket dinners that feels a little special without asking much from you. It takes the cozy flavors people love in classic chicken and pastry dishes and turns them into an easy casserole format, with creamy chicken tucked under a buttery puff pastry topping. It is exactly the kind of recipe I keep around for busy weeknights, casual family birthdays, or those evenings when I want something homemade and nostalgic without making a huge mess.
Serve this casserole with a simple green salad, roasted green beans, or steamed broccoli to balance the rich creamy filling. If you are feeding a bigger group, a side of buttered carrots or mashed potatoes works beautifully too, and for a really easy dinner setup, just add cranberry sauce or a light fruit salad for a little contrast.
Oven Baked 4-Ingredient Chicken Wellington Casserole
Servings: 6
Ingredients
3 cups cooked chicken, shredded or diced
1 can (10.5 ounces) condensed cream of chicken soup
1 sheet frozen puff pastry, thawed
1 cup shredded mozzarella or Swiss cheese
Directions
1. Preheat your oven to 400°F and lightly grease a 9x13-inch baking dish or a similar 2-quart casserole dish.
2. In a large bowl, stir together the cooked chicken, condensed cream of chicken soup, and shredded cheese until evenly combined.
3. Spread the chicken mixture into the prepared baking dish in an even layer.
4. Lay the puff pastry sheet over the top of the filling, trimming or gently stretching it as needed to fit. Lightly press the edges toward the sides of the dish and cut a few small slits in the top so steam can escape.
5. Bake for 25 to 30 minutes, or until the pastry is puffed and deeply golden brown and the filling is hot and bubbly around the edges.
6. Let the casserole rest for 5 to 10 minutes before serving so the filling can settle slightly, then scoop onto plates and serve warm.
Variations & Tips
Rotisserie Chicken Shortcut: This is one of my favorite ways to make this recipe fit into a busy workweek. Store-bought rotisserie chicken saves time and gives you plenty of flavor, and it is perfect when you want dinner on the table fast.
Cheese Swap: Mozzarella gives you a mild, melty filling, while Swiss adds a more classic chicken Wellington flavor. If your family likes a sharper bite, a mix of Swiss and provolone also works nicely.
Make-Ahead Tip: You can mix the filling and spread it in the baking dish a day ahead, then cover and refrigerate it. Add the puff pastry right before baking so it stays crisp and bakes up nicely golden.
Crisper Pastry Tip: If your puff pastry is getting too soft while you work, pop it back into the refrigerator for a few minutes before placing it over the casserole. Cold pastry puffs better in the oven and gives you those flaky layers everyone wants.