This oven baked 4-ingredient chicken Wellington casserole is the kind of comforting supper that feels a little special without asking much from the cook. It has that old-fashioned Sunday dinner charm, with tender chicken tucked under a creamy filling and a flaky puff pastry top that bakes up beautifully golden. It is likely inspired by classic chicken Wellington flavors, but in casserole form it is much easier to put on the table for a family meal or a cozy gathering.

Serve this casserole with simple sides that let the rich filling and buttery pastry shine. A crisp green salad, steamed green beans, roasted carrots, or buttered peas all work well, and for bigger appetites I like to add mashed potatoes or rice to catch every bit of the creamy sauce. If you are serving guests, a bowl of fruit and warm rolls round things out nicely.

Oven Baked 4-Ingredient Chicken Wellington Casserole

Servings: 6

Chicken Wellington casserole fresh from the oven
Chicken Wellington casserole fresh from the oven

Ingredients

3 cups cooked chicken, chopped or shredded

1 can condensed cream of chicken soup
1 sheet frozen puff pastry, thawed
1 cup frozen mixed vegetables

Directions

1. Preheat the oven to 400°F and lightly grease a rectangular glass baking dish.

2. In a large bowl, stir together the cooked chicken, condensed cream of chicken soup, and frozen mixed vegetables until everything is evenly coated.

3. Spread the chicken mixture evenly into the prepared baking dish.

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

5. Bake for 30 to 35 minutes, or until the pastry is puffed and deep 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.

Variations & Tips

Shortcut chicken: Rotisserie chicken makes this recipe especially easy on a busy evening. Just remove the skin, chop the meat, and you are ready to mix the filling.

Picky eater version: If your family is not fond of mixed vegetables, use just peas or leave the vegetables out and serve them on the side. The casserole will still be creamy and delicious.

Make it extra savory: A handful of sautéed mushrooms or a spoonful of Dijon mustard can be stirred into the filling if you want a flavor closer to a classic chicken Wellington. Keep in mind that this turns it into more than a 4-ingredient version, but it is lovely for company.

Puff pastry tip: Thaw the pastry in the refrigerator so it stays cold but flexible. If it gets too warm before baking, pop the assembled casserole into the fridge for 10 minutes to help the pastry puff nicely in the oven.

Make-ahead note: You can mix the filling and spread it in the dish ahead of time, then add the pastry just before baking. That keeps the top from getting soggy and makes dinnertime much simpler.