This oven baked 3-ingredient chicken Wellington casserole is the kind of simple, comforting supper that feels a little special without asking much from the cook. It has that vintage church-supper charm so many family recipes do, turning a few pantry and freezer staples into a bubbling casserole with creamy chicken tucked under a golden, flaky crust. If you love old-fashioned holiday casseroles or need an easy meal that still feels cozy and celebratory, this one delivers beautifully.

Serve this casserole with simple sides that let its rich, creamy filling shine, like steamed green beans, buttered peas, roasted carrots, or a crisp green salad. For a holiday-style meal, I like it with cranberry sauce, mashed potatoes, or a fruit salad on the side, and warm rolls make it feel especially comforting for family dinners.

Oven Baked 3-Ingredient Chicken Wellington Casserole

Servings: 6

Golden puff pastry topped chicken casserole in a white ceramic dish
Golden puff pastry topped chicken casserole in a white ceramic dish

Ingredients

2 cups cooked chicken, chopped or shredded

1 can condensed cream of mushroom soup, undiluted
1 sheet frozen puff pastry, thawed

Directions

1. Preheat the oven to 400°F and lightly grease a small casserole dish or 8-inch square baking dish.

2. In a medium bowl, stir the cooked chicken and condensed cream of mushroom soup together until evenly combined.

3. Spread the chicken mixture into the prepared casserole dish in an even layer.

4. Lay the thawed puff pastry sheet over the top, trimming if needed so it fits the dish. Gently tuck the edges just inside the dish and cut a few small slits in the pastry to let steam escape.

5. Bake for 25 to 30 minutes, or until the pastry is puffed and deep golden brown and the filling is hot and bubbling around the edges.

6. Let the casserole rest for 5 to 10 minutes before serving so the filling can set slightly, then scoop out warm portions.

Variations & Tips

Kid-Friendly Version: If your family prefers a plainer flavor, use finely chopped chicken so every bite feels soft and uniform, and serve with buttered noodles or peas. This casserole is especially nice for picky eaters because the filling stays mild and creamy.

Make It Stretch: To feed a few extra people, add a side of mashed potatoes, rice, or extra vegetables and serve slightly smaller portions. Since the casserole is rich, a little goes a long way on a holiday table or potluck spread.

Pastry Tip: Keep the puff pastry cold but thawed before using so it bakes up flaky instead of soft and heavy. If it gets too warm while you work, pop it back into the refrigerator for a few minutes before baking.

Easy Upgrade: Even though the classic version uses only three ingredients, a sprinkle of black pepper, a spoonful of sautéed onions, or a handful of cooked mushrooms can be added if you want a little more flavor while keeping the spirit of the original recipe.