Creamy, cheesy, and piled high with golden crispy onions, this French Onion Chicken Orzo Casserole is pure comfort in a baking dish. It takes everything I love about classic French onion soup—the slow-caramelized onions, the deep savory flavor, the gooey cheese—and tucks it into a cozy pasta dinner.

This is the kind of meal I reach for on chilly nights or on those busy weekdays when everyone is hungry at the same time. Tender shredded chicken and creamy orzo cook together in one pan, then bake until bubbly with a Gruyère blanket on top. A final shower of crispy onions and fresh parsley makes it look (and taste) like something straight from a little French bistro.

What Makes This French Onion Chicken Orzo Casserole So Cozy?

For me, it’s all about layers of flavor and texture. Slowly caramelized onions bring sweetness and depth that you just can’t fake. Orzo cooks directly in a silky, onion-infused sauce so every little grain is coated in flavor. Shredded chicken adds protein and heft, while Gruyère melts into that classic stretchy, nutty topping.

I also love that this casserole feels special but doesn’t ask for anything fussy. You can use leftover or rotisserie chicken, pantry staples like broth and onions, and a bag of store-bought crispy onions for the crunch on top. It’s hearty enough for Sunday dinner but easy enough for a weeknight.

Ingredients for the French Onion Chicken Orzo Casserole

This casserole leans on simple ingredients that work hard in the flavor department. Here’s what I use and why each one matters.

Yellow onions – The star of the show. Slowly cooking them draws out their natural sweetness and gives the whole casserole that classic French onion flavor.
Unsalted butter & olive oil – Using both keeps the onions from burning and adds rich, rounded flavor to the base of the dish.
Granulated sugar – Just a pinch helps the onions caramelize more evenly and quickly without making the dish taste sweet.
Kosher salt & black pepper – Essential for seasoning every layer so the final casserole tastes balanced and not flat.
Garlic – Adds a savory backbone and keeps the onion flavor from leaning too one-note.
Thyme – A little dried or fresh thyme brings a cozy, herby note that pairs perfectly with caramelized onions and chicken.
All-purpose flour – This is what thickens the sauce so it clings to the orzo and chicken instead of staying thin and brothy.
Dry white wine (or extra broth) – Deglazes the pan and lifts all the caramelized bits from the bottom, building a deep, almost restaurant-style flavor.
Chicken broth – The main cooking liquid for the orzo, adding savory depth as it absorbs into the pasta.
Milk or half-and-half – Gives the sauce its creamy, velvety texture without feeling too heavy.
Orzo pasta – Small, rice-shaped pasta that cooks quickly and turns wonderfully silky in the creamy sauce.
Cooked shredded chicken – Rotisserie chicken works beautifully and makes this recipe a smart way to use leftovers.
Gruyère cheese – Melts into a nutty, stretchy topping that makes this casserole taste just like French onion soup.
Mozzarella cheese – Adds extra meltiness and soft, gooey cheese pulls in every scoop.
Crispy French fried onions – For that irresistible crunch on top and even more French onion vibes.
Fresh parsley – A sprinkle right before serving brightens up the rich flavors and adds a fresh pop of color.

How To Make the French Onion Chicken Orzo Casserole

Once the onions are caramelized, everything comes together in one pan and finishes in the oven. I love that I can build the sauce, cook the orzo, and bake the casserole with almost no extra dishes.

Step 1: Prep the pan and preheat the oven

Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with butter or nonstick spray and set it aside. Having the dish ready makes it easy to transfer the orzo mixture once it’s thick and creamy.

Step 2: Slowly caramelize the onions

In a large, deep skillet or Dutch oven, heat the butter and olive oil over medium heat. Add the sliced onions, a pinch of salt, and the sugar. Cook, stirring often, for 20–25 minutes, until the onions are deeply golden and caramelized. If they start browning too quickly, drop the heat slightly and add a splash of water to loosen any bits on the bottom.

Step 3: Build the flavor base

Stir in the garlic and thyme and cook for about 1 minute, just until fragrant. Sprinkle the flour over the onions and stir well so every strand is coated. Let the flour cook for 1–2 minutes to remove any raw taste.

Step 4: Deglaze and make the creamy sauce

Pour in the white wine (or extra broth), stirring and scraping the bottom of the pan to release all those caramelized bits. Let it simmer for 1–2 minutes. Slowly whisk in the chicken broth and then the milk, stirring until the sauce is smooth and starting to thicken.

Step 5: Add the orzo and chicken

Stir the uncooked orzo into the sauce, making sure it’s evenly distributed and submerged. Add the shredded chicken and a little more salt and pepper to taste. Let the mixture simmer gently for 5 minutes, stirring often, just until the orzo starts to soften but isn’t fully cooked.

Step 6: Stir in the cheese and transfer to the baking dish

Turn off the heat and stir in about half of the Gruyère and all of the mozzarella until just melted and creamy. The sauce will be thick and luxurious. Transfer the mixture to your prepared baking dish, spreading it into an even layer. Sprinkle the remaining Gruyère evenly over the top.

Step 7: Bake until bubbly, then add the crispy onions

Bake the casserole for 20–25 minutes, or until the orzo is tender and the edges are bubbling. Carefully pull the dish out of the oven, scatter the crispy French fried onions over the top, and return it to the oven for another 5 minutes so the onions can toast up even more.

Step 8: Rest, garnish, and serve

Let the casserole rest for about 5–10 minutes before serving so it can thicken slightly and slice more cleanly. Finish with a sprinkle of fresh parsley, then scoop big, cozy portions into bowls.

Serving and Storing French Onion Chicken Orzo Casserole

I like to serve this casserole piping hot with extra crispy onions on the table so everyone can add a little more crunch if they want. A handful of fresh herbs or an extra grind of black pepper over each serving makes it feel restaurant-worthy.

Leftovers keep really well, which makes this a great meal-prep option. Store cooled casserole in an airtight container in the fridge for up to 3–4 days. Reheat portions in the microwave with a splash of broth or milk to loosen the sauce, or warm the whole dish in the oven, covered with foil, until heated through. The crispy onions will soften as they sit, but you can always add a fresh handful after reheating.

You can also freeze baked portions for up to 2 months. Thaw overnight in the fridge and reheat gently, adding a bit of extra cheese or a spoonful of broth if it seems dry.

What to Serve With French Onion Chicken Orzo Casserole?

This casserole is rich and satisfying on its own, but a simple side or two turns it into a full dinner spread.

Garlic Butter Green Beans

Quickly sauté fresh green beans with butter, garlic, and a squeeze of lemon. The bright, snappy veggies cut through the creaminess of the casserole.

Simple House Salad

A big bowl of mixed greens with cherry tomatoes, cucumbers, and a light vinaigrette keeps things fresh. I love the contrast of crisp salad next to a warm, cheesy bake.

Roasted Vegetables

Toss carrots, broccoli, or Brussels sprouts with olive oil, salt, and pepper, then roast until caramelized. The roasted edges echo the sweetness of the caramelized onions.

Crusty Bread or Garlic Toast

Lean all the way into the French onion soup theme and serve thick slices of toasted baguette or buttery garlic toast for dunking in the creamy sauce.

Crisp Cucumber Salad

For something cool and crunchy, a simple cucumber salad with dill and vinegar is perfect alongside this cozy casserole.

Want More Cozy Casserole Ideas?

If you love this French Onion Chicken Orzo Casserole, you’ll probably enjoy these other comfort-food favorites too:

Try my French Onion Beef Rice Casserole when you’re craving all the French onion flavor with hearty beef and rice.
Make One Pot French Onion Chicken and Rice for another easy, skillet-style dinner with minimal cleanup.
Bake a pan of Hashbrown Chicken Casserole when you want ultra-creamy potato comfort with plenty of cheese.
Keep things fun and family-friendly with Chicken Crescent Roll Casserole, a cozy bake topped with buttery, flaky crescents.

Save This Pin For Later

Save this French Onion Chicken Orzo Casserole to your favorite Pinterest board so it’s easy to find the next time a creamy, cheesy dinner craving hits.

Tried it with a twist—maybe extra herbs, a different cheese blend, or a splash of Worcestershire in the sauce? I’d love to hear how it turned out. Drop your tips, variations, or questions in the comments so we can all swap ideas.

Need more inspiration? Explore my daily kitchen creations on SavorQueen.com on Pinterest. Your next favorite might be waiting there.