Chicken Cordon Bleu Casserole

I first created this Chicken Cordon Bleu Casserole when I was craving the fancy restaurant dish but didn't have the patience (or honestly, the skill) to pound, stuff, roll, and bread individual chicken breasts. After a few tries, I landed on this casserole version that delivers all the flavor with a fraction of the effort. Now it's become my go-to when hosting dinner parties because it always impresses, but secretly takes just minutes of hands-on work. My sister-in-law actually requested it for our last family gathering, not realizing how simple it is to make!

The first time I made this for company, my friend's husband took a bite and immediately said, "This is not a casserole... this is too good to be a casserole!" That's when I knew this recipe was a keeper. It's become my secret weapon for dinner parties because it looks and tastes impressive while giving me time to actually enjoy my guests instead of being stuck in the kitchen.

Simple Ingredients

Cooked Chicken - 4 cups shredded or diced.
Ham - 1 cup diced (about 4-6 thick slices).
Swiss Cheese - 2 cups shredded, plus ¼ cup grated for the sauce.
Broccoli - 3 cups florets, blanched.
Butter - 3 tablespoons, plus 2 tablespoons melted for the topping.
Garlic - 2 cloves minced.
All-Purpose Flour - 3 tablespoons.
Chicken Broth - 1 cup.
Milk - 1 cup.
Dijon Mustard - 2 tablespoons.
Parmesan Cheese - ¼ cup grated (plus additional for the sauce).
Chicken Bouillon Powder - 1 teaspoon.
Panko Breadcrumbs - 1 cup.
Salt and Pepper - To taste.

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Easy Preparation

Create The Signature Sauce

Start by melting 3 tablespoons of butter in a saucepan over medium heat. Add 2 minced garlic cloves and cook just until fragrant, about 30 seconds – don't let it brown or it'll turn bitter. Reduce the heat to low and whisk in 3 tablespoons of all-purpose flour to create a roux, cooking for about a minute to remove that raw flour taste. Gradually pour in 1 cup of chicken broth and 1 cup of milk, whisking constantly to prevent lumps. This is where patience pays off – add the liquid slowly and keep whisking for a smooth, velvety sauce. Once incorporated, whisk in 2 tablespoons of Dijon mustard, 1 teaspoon of chicken bouillon powder, and 1/4 cup of grated Parmesan cheese. Let the sauce simmer gently for 2-3 minutes until it thickens to coat the back of a spoon. Season with salt and pepper to taste, remembering that ham and cheese will add saltiness to the final dish.

Prep Your Vegetables

While making the sauce, bring a pot of generously salted water to a boil. Add about 3 cups of broccoli florets and blanch them for just 2-3 minutes until they're bright green and crisp-tender. Immediately drain and rinse under cold water to stop the cooking process – this keeps them vibrant and prevents them from becoming mushy in the casserole.

Layer With Love

Preheat your oven to 400°F (200°C) and lightly grease a 9x13 inch (23x33 cm) baking dish. Spread the cooked chicken in an even layer on the bottom. This forms the foundation of your casserole, so make sure it's distributed evenly. Top with your blanched broccoli and diced ham, creating a colorful middle layer. Pour the Dijon cream sauce evenly over everything, allowing it to seep down between the layers. Sprinkle 2 cups of shredded Swiss cheese and an additional 1/4 cup of grated Parmesan cheese over the top.

Create The Crispy Crown

In a small bowl, mix 1 cup of Panko breadcrumbs with 2 tablespoons of melted butter, using a fork to ensure all the crumbs are evenly coated. This step is key for achieving that beautiful golden-brown top. Sprinkle this mixture evenly over the cheese layer, creating the final touch that will become irresistibly crispy during baking.

Bake To Golden Perfection

Place the casserole in your preheated oven and bake uncovered for about 30 minutes, or until the top is beautifully golden and the edges are bubbling. I sometimes turn on the broiler for the last minute or two to get the top extra crispy, but watch it carefully to prevent burning. Let the casserole rest for about 5 minutes before serving – this helps it set up nicely for cleaner serving.

I learned the importance of proper sauce consistency through trial and error. My first attempt was made with a sauce that was too thick, which resulted in a somewhat dry casserole after baking. Now I make sure my sauce is a bit thinner than I think it should be, as it will continue to thicken during baking from both the heat and the starch in the other ingredients. I aim for the consistency of a thick cream soup – something that pours easily but still coats the back of a spoon.

Creative Variations

While I love the classic version of this casserole, I've experimented with several variations over the years that have been equally successful: Mediterranean Twist - Substitute the ham with prosciutto, use fontina cheese instead of Swiss, and add a layer of roasted red peppers. Sprinkle in some fresh thyme and a squeeze of lemon juice to the sauce for a brighter flavor profile. Spicy Kick - Add a diced jalapeño to the sauce and substitute pepper jack for half of the Swiss cheese. A dash of hot sauce in the Dijon cream sauce adds depth without overwhelming heat. This version is my husband's favorite – he puts hot sauce on everything! Loaded Vegetable Version - For a more veggie-forward dish, add sautéed mushrooms, spinach, and roasted red peppers along with the broccoli. The vegetables release moisture as they cook, so I sometimes add an extra tablespoon of flour to the sauce to compensate. Gluten-Free Adaptation - Use gluten-free flour and breadcrumbs without any loss of flavor. I've made this for my gluten-sensitive friend by using almond flour in the sauce (though it needs a bit more) and crushed Rice Chex mixed with Parmesan for the topping.

Serving Suggestions

This casserole is hearty enough to stand on its own, but I like to balance its richness with something light on the side. A simple green salad with a tangy vinaigrette makes the perfect counterpoint. For a more substantial meal, some crusty bread for sopping up the delicious sauce is never a bad idea. For wine pairing, a crisp white like Sauvignon Blanc or a light-bodied Chardonnay complements the creamy, cheesy flavors beautifully. If you prefer red, a Pinot Noir works surprisingly well with the ham and cheese elements. When serving for company, I like to bring the whole bubbling casserole to the table in my prettier baking dish. There's something about that moment of revealing the golden, crispy top that always elicits "oohs" and "aahs" from guests.

Storage Smarts

This casserole keeps beautifully in the refrigerator for up to 4 days, making it perfect for planned leftovers. To reheat individual portions, microwave on medium power for about 2 minutes, then finish with a minute on high to help re-crisp the top slightly. For larger amounts, reheat covered with foil in a 325°F (160°C) oven for about 20 minutes, then uncover for the last 5 minutes to restore some crispness to the top. The casserole also freezes remarkably well, which is why I often make a double batch and freeze one for future use. To freeze, allow the casserole to cool completely, then cover tightly with plastic wrap followed by aluminum foil. It will keep for up to 3 months. Thaw overnight in the refrigerator before reheating as directed above, though you may need to add an extra 10-15 minutes to the reheating time.

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Chef's Wisdom

Cheese Grating Tip - For the creamiest sauce, grate your own cheese rather than using pre-shredded, which contains anti-caking agents that can affect melting. Roux Rule - The key to a smooth sauce is adding cold liquid to a hot roux (or hot liquid to a cold roux) to prevent lumps. Flavor Boost - Add a pinch of ground nutmeg to the cream sauce for a subtle warmth that complements the cheese beautifully.

I've made this Chicken Cordon Bleu Casserole countless times now, for family dinners, potlucks, and even as a meal for new parents. What I love most is how it transforms a fancy French-inspired dish into something approachable and comforting without losing its special-occasion feel. It's proof that a little culinary shortcut doesn't mean sacrificing flavor, and sometimes the simplified version can become the favorite in its own right. Whether you're looking to impress dinner guests or just wanting to elevate a weeknight family meal, this casserole delivers restaurant-quality flavor with home-cooked comfort.

Frequently Asked Questions

→ Can I use leftover chicken for this recipe?

Absolutely! Leftover roasted chicken or rotisserie chicken works perfectly. You'll need about 4 cups of cooked, shredded or diced chicken.

→ Can I make this casserole ahead of time?

Yes! Assemble the casserole up to 24 hours ahead, cover and refrigerate. Add the breadcrumb topping just before baking, and you may need to add 5-10 minutes to the baking time.

→ What can I substitute for Swiss cheese?

Gruyère is an excellent substitute, but provolone or mozzarella would also work well. The flavor will be slightly different but still delicious.

→ Can I freeze this casserole?

Yes, it freezes well for up to 3 months. Thaw overnight in the refrigerator and reheat in a 350°F oven for 25-30 minutes or until heated through.

→ What sides go well with this casserole?

A simple green salad, roasted vegetables, or garlic bread are all excellent pairings with this rich casserole.