Can I make this casserole ahead of time?

Absolutely! You can prepare the casserole up to the point of adding the toppings, then refrigerate for up to 24 hours. When ready to serve, bring to room temperature, add the croutons and cheese, then bake as directed, adding about 5-10 minutes to the baking time.

What if I don't have an oven-safe pot?

No problem! Prepare the pasta mixture as directed, then transfer it to a 9x13 baking dish before adding the croutons and cheese. Bake as directed in the recipe for equally delicious results.

Can I use a different type of pasta?

Yes! While rigatoni works beautifully because its shape holds the sauce well, other medium-sized pasta shapes like penne, ziti, or fusilli will work nicely too. Avoid long pasta like spaghetti or linguine, which can be awkward in a casserole format.

Is there a substitute for dry sherry?

You can omit the sherry entirely, or substitute with dry white wine, vermouth, or even a splash of balsamic vinegar for a different but complementary flavor profile. Each will bring its own character to the dish while maintaining that special depth.

French Onion Pasta Casserole Recipe

This French Onion Pasta Casserole transforms the beloved flavors of classic French onion soup into a hearty, comforting pasta dish that’s sure to satisfy. With sweet caramelized onions, savory beef broth, al dente rigatoni, and a crispy, cheesy topping, this casserole brings together the best of two comfort food worlds in one delicious meal. Perfect for family dinners or entertaining, this casserole will quickly become a requested favorite in your recipe collection.

Why You’ll Love This Recipe

Comfort Food Fusion: Combines the rich, savory flavors of French onion soup with the heartiness of a pasta casserole — truly the best of both worlds.
Make-Ahead Friendly: Prepare the components ahead of time and assemble just before baking, making it perfect for busy weeknights or entertaining.
Crowd-Pleaser: The familiar flavors appeal to both adults and kids, while the unique combination offers something special that will impress dinner guests.
One-Pot Wonder: Most of the cooking happens in a single pot, minimizing cleanup and making the cooking process straightforward.

Ingredients You’ll Need

Rigatoni: The perfect pasta choice for this dish as its tubular shape catches the delicious sauce and stands up well to the longer cooking time.
Yellow onions: The star of the show! These transform into sweet, caramelized goodness that gives the dish its characteristic French onion flavor.
Beef broth: Provides that rich, savory base that makes French onion soup so satisfying. Use good quality broth for the best flavor.
Olive oil and butter: The combination allows for higher heat cooking while still delivering rich flavor for caramelizing the onions.
Garlic: Adds depth and aromatic character to complement the sweet onions.
Dry sherry: Optional but recommended for that authentic French onion soup flavor profile. The alcohol cooks off, leaving behind complex flavor.
Dried thyme: A classic herb that pairs beautifully with the onions and broth, providing earthy notes.
Salt and pepper: Essential for balancing and enhancing all the flavors in the dish.
Garlic croutons: Creates a crunchy top layer reminiscent of the bread in traditional French onion soup.
Gruyere cheese: The traditional choice for French onion soup with its perfect melting properties and nutty flavor. Provolone makes a great substitute.

Note: You’ll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Variations

Protein Additions

Add shredded rotisserie chicken or browned Italian sausage for a heartier meal that still maintains the French onion character.

Vegetarian Version

Substitute vegetable broth for beef broth and add mushrooms during the onion caramelization process for extra umami depth.

Gluten-Free Option

Use your favorite gluten-free pasta and replace the croutons with crushed gluten-free crackers mixed with a bit of butter and herbs.

Extra Vegetables

Add sautéed mushrooms, bell peppers, or spinach for additional nutrients and flavor variations.

How to Make French Onion Pasta Casserole

Step 1: Caramelize the Onions

Heat olive oil in a large, oven-safe pot over medium-high heat. Add sliced onions and cook until they begin to soften. Reduce heat to medium-low and continue cooking, stirring occasionally, until the onions transform into a deep golden brown color. This process takes patience—about 15-25 minutes—but creates the essential sweet, complex base flavor.

Step 2: Build the Flavor Base

Add butter and minced garlic to the caramelized onions, cooking until the butter melts and the garlic becomes fragrant. The combination of caramelized onions and garlic creates an irresistible aroma that will fill your kitchen.

Step 3: Create the Broth

Pour in beef broth and dry sherry, if using. Season with dried thyme, salt, and pepper. Bring the mixture to a gentle simmer and let it cook for 10 minutes, allowing the flavors to meld together beautifully.

Step 4: Cook the Pasta

While the broth simmers, preheat your oven to 350°F. Add rigatoni directly to the simmering broth in the pot. Let it cook for about 10 minutes, stirring occasionally to ensure even cooking. The pasta will absorb the flavorful broth as it cooks.

Step 5: Add the Topping

Remove the pot from heat once the pasta is cooked. Spread garlic croutons evenly over the top of the pasta, gently pressing them into the mixture. Sprinkle shredded gruyere or provolone cheese over the crouton layer for that classic French onion finish.

Step 6: Bake to Perfection

Transfer the pot to the preheated oven and bake for 20 minutes, until the cheese is bubbly and beautifully golden brown. Let the casserole rest for 5 minutes before serving to allow the flavors to settle.

Pro Tips for Making the Recipe

Patience with Onions: Don’t rush the caramelization process—this is where the magic happens. Low and slow cooking develops the sweet, complex flavor that makes this dish special.
Al Dente Pasta: Cook the pasta just until al dente in the broth, as it will continue to cook in the oven. This prevents mushy pasta in the final dish.
Cheese Selection: While gruyere is traditional, a combination of gruyere and provolone creates an excellent balance of flavor and superior melting quality.
Layering: For maximum flavor and texture contrast, ensure your crouton layer is evenly distributed before adding the cheese topping.
Broiler Finish: For an extra golden, bubbly cheese top, switch your oven to broil for the final 1-2 minutes of cooking (watching carefully to prevent burning).

How to Serve

Main Course Pairings

Serve this rich casserole with a crisp green salad dressed with a light vinaigrette to balance the richness of the dish.

Wine Pairing

A medium-bodied red wine like Pinot Noir or Beaujolais complements the sweet onions and savory broth beautifully.

Garnishes

Sprinkle with fresh thyme leaves just before serving for a pop of color and fresh herb flavor.

Make Ahead and Storage

Storing Leftovers

Store leftovers in an airtight container in the refrigerator for up to 3 days. The flavors often develop and improve overnight, making this an excellent make-ahead dish.

Freezing

You can freeze the casserole without the crouton and cheese topping for up to 3 months. Thaw overnight in the refrigerator before adding the toppings and baking.

Reheating

Reheat individual portions in the microwave for 2-3 minutes. For larger portions, cover with foil and reheat in a 325°F oven until warmed through (about 20 minutes), removing the foil for the last 5 minutes to re-crisp the top.

FAQs

Can I make this casserole ahead of time?

Absolutely! You can prepare the casserole up to the point of adding the toppings, then refrigerate for up to 24 hours. When ready to serve, bring to room temperature, add the croutons and cheese, then bake as directed, adding about 5-10 minutes to the baking time.
What if I don’t have an oven-safe pot?

No problem! Prepare the pasta mixture as directed, then transfer it to a 9×13 baking dish before adding the croutons and cheese. Bake as directed in the recipe for equally delicious results.
Can I use a different type of pasta?

Yes! While rigatoni works beautifully because its shape holds the sauce well, other medium-sized pasta shapes like penne, ziti, or fusilli will work nicely too. Avoid long pasta like spaghetti or linguine, which can be awkward in a casserole format.
Is there a substitute for dry sherry?

You can omit the sherry entirely, or substitute with dry white wine, vermouth, or even a splash of balsamic vinegar for a different but complementary flavor profile. Each will bring its own character to the dish while maintaining that special depth.

Final Thoughts

This French Onion Pasta Casserole is comfort food at its finest—familiar yet exciting, simple yet sophisticated. The marriage of sweet caramelized onions, savory broth, perfectly cooked pasta, and that irresistible cheesy crust creates a dish that’s greater than the sum of its parts. Whether you’re sharing it with family on a weeknight or serving it to guests at a dinner party, this casserole promises to deliver both comfort and excitement in every bite.