Name: French Onion Stuffed Shells Recipe
Prep time: 20 min
Cook time: 50 min
Total time: 1 h 10 min
Cuisine: French-American
Ingredients: 4 sweet onions, thinly sliced; Kosher salt and pepper, to taste; ½ teaspoon dried thyme; 4 tablespoons unsalted butter; 2 garlic cloves, minced; 8 ounces jumbo pasta shells (about 20 shells); 2 cups ricotta cheese; 1 large egg; 1 cup grated Gruyère cheese; ¼ cup grated Parmesan cheese (plus more for topping); Salt and pepper, to taste; ½ teaspoon dried thyme (from filling mixture); 1 tablespoon flour; 1½ cups chicken stock (or beef/vegetable stock); ⅓ cup cream; 1 cup grated mozzarella cheese (for topping); ¼ cup seasoned breadcrumbs (for topping); Fresh parsley or thyme for garnish

If you’re craving a cozy, comforting meal with layers of rich flavor and melty cheese, then the French Onion Stuffed Shells Recipe is your next must-try. This dish takes the classic caramelized onion sweetness of French onion soup and transforms it into a beautifully baked Italian-American casserole starring jumbo pasta shells stuffed with a luscious blend of cheeses and herbs. It’s an indulgent, crowd-pleasing dinner that feels both elegant and soul-soothing, perfect for family dinners or impressing friends. Get ready to fall in love with every cheesy, savory bite!

Ingredients You’ll Need

A black pan is shown with sliced onions being cooked, slightly translucent with light brown edges, and small sprigs of thyme scattered among them. A wooden spatula is adding a small piece of melting white butter to the pan. The background has a soft blur and the scene is bright with natural lighting, steam gently rising from the pan. Photo taken with an iphone --ar 4:5 --v 7

The beauty of this French Onion Stuffed Shells Recipe lies in its simple ingredients, each playing a key role to create a symphony of flavors and textures. From sweet, slow-cooked onions to creamy ricotta and the wonderfully nutty Gruyère cheese, these components come together to make the dish truly shine.

Sweet onions: Thinly sliced for caramelization, they bring natural sweetness and depth.
Kosher salt and pepper: Essential for seasoning and enhancing all the flavors.
Dried thyme: Adds an earthy, herbal note to complement the onions and cheeses.
Jumbo pasta shells: The perfect vessel for the cheesy filling, tender yet sturdy.
Ricotta cheese: Creamy and mild, it creates the luscious filling base.
Garlic cloves: Minced to provide aromatic sharpness without overpowering.
Unsalted butter: Used to caramelize the onions and build richness.
Large egg: Helps bind the ricotta mixture for a smooth filling.
Gruyère cheese: Grated for a smoky, slightly sweet flavor and gooey meltiness.
Parmesan cheese: Adds salty, nutty depth to both the filling and topping.
Flour: Incorporated to thicken the delicious onion sauce.
Seasoned breadcrumbs: For a crisp, golden topping that contrasts the creamy pasta.
Stock (chicken, beef, or vegetable): Forms the savory base of the rich onion sauce.
Cream: Enriches the sauce, making every bite silky smooth.
Mozzarella cheese: Sprinkled on top to melt into a bubbly, inviting crust.
Fresh parsley or thyme: Garnishes that bring fresh herbal brightness.

TIP

You’ll find the full ingredient list, instructions, and print option in the recipe card below.

How to Make French Onion Stuffed Shells Recipe

Step 1: Caramelize the Onions

Begin by melting the butter in a large oven-safe skillet over medium heat. Add the thinly sliced sweet onions along with kosher salt, pepper, and dried thyme. This isn’t a quick process; slow cooking the onions for about 30 minutes while stirring often allows their natural sugars to develop into a deep, golden caramelized flavor that’s the soul of this dish. Towards the end of this stage, stir in minced garlic and turn off the heat to avoid burning the garlic.

Step 2: Cook the Jumbo Shells

While the onions are caramelizing, bring a pot of salted water to a boil and cook the jumbo pasta shells according to package directions. Be careful not to overcook them—they should be tender but still hold their shape for stuffing. Drain and lay them out on a baking sheet to cool slightly and prevent sticking.

Step 3: Prepare the Cheese Filling

In a mixing bowl, combine ricotta cheese, a beaten egg, grated Gruyère, parmesan cheese, salt, pepper, and a pinch of thyme for extra herbal aroma. Add half of the caramelized onion mixture and fold gently until smooth and unified. This creamy filling will be nestled inside each pasta shell, making every bite irresistibly rich and flavorful.

Step 4: Fill the Shells

Carefully spoon the cheese and onion mixture into each cooled shell, filling them generously but without tearing the pasta. Set these aside—you’ll return to them shortly for assembly.

Step 5: Make the French Onion Sauce

Return the remaining caramelized onions to the skillet and sprinkle the flour over them. Cook, stirring constantly, for 1 to 2 minutes to cook off the raw flour taste. Gradually whisk in your choice of stock—chicken, beef, or vegetable—and let the sauce simmer until it thickens, about 3 to 5 minutes. Stir in the cream to add luxurious silkiness that will cradle the stuffed shells.

Step 6: Assemble and Bake

Nestle the filled shells open-side up right into the onion sauce in the skillet. Sprinkle a generous layer of shredded mozzarella cheese and evenly distribute the seasoned breadcrumbs on top to create that coveted golden crust. Bake the entire skillet in a preheated 400°F oven for 20 to 25 minutes until the cheese is bubbly and lightly browned. Finish with extra parmesan and fresh herbs to elevate each serving visually and flavor-wise.

How to Serve French Onion Stuffed Shells Recipe

A white pan sits on a gas stove with a white marbled counter beneath it. Inside the pan, there are three visible layers: the bottom layer is a thick red tomato sauce with a chunky texture, the middle layer consists of large shell pasta pieces that are creamy yellow and smooth, placed unevenly on the sauce, and the top layer being scoops of white ricotta cheese in the center being held by a spoon in a woman's hand, mixing gently with one shell pasta on top. The background shows a window with soft light coming through and a small green plant blurred in the back. Photo taken with an iphone --ar 4:5 --v 7

Garnishes

Fresh parsley or thyme sprigs are perfect for adding a pop of green and a hint of brightness that cuts through the rich, cheesy depth. A dusting of extra parmesan right before serving amps up the savory appeal.

Side Dishes

This dish pairs wonderfully with a crisp green salad tossed in a light vinaigrette for a refreshing contrast. Roasted vegetables or a simple sauté of garlic spinach also complement the richness without competing with it.

Creative Ways to Present

For a fun twist, serve the stuffed shells on individual plates garnished with a drizzle of balsamic glaze or a dollop of sour cream to echo the French onion soup origins. You could also scoop the filling as a dip for crusty bread at a dinner party, turning this comforting meal into an elegant appetizer option.

Make Ahead and Storage

Storing Leftovers

If you have leftovers, simply cover the baked French Onion Stuffed Shells Recipe tightly with foil or transfer to an airtight container and refrigerate. They will stay fresh for up to 3 days and taste even better the next day after the flavors meld further.

Freezing

To freeze, bake the assembled shells without the mozzarella and breadcrumbs topping, then cool completely. Flash freeze them individually on a baking sheet before transferring to a freezer-safe bag. Freeze for up to 2 months, then add toppings just before baking from frozen.

Reheating

Reheat leftovers gently in a 350°F oven covered with foil to prevent drying out, about 20 minutes or until heated through. Alternatively, microwave individual portions covered with a damp paper towel for a quicker option though baking maintains the best texture.

FAQs

Can I use a different type of cheese for the filling?

Absolutely! While Gruyère and parmesan add signature flavors, you can swap them with fontina, provolone, or even sharp cheddar depending on your preference or what you have on hand. Just make sure to balance the strong and mild cheeses.

Is it necessary to caramelize the onions for the full 30 minutes?

Yes, patience is key here. Slow caramelization is what develops the deep, sweet flavor that makes this dish stand out, so resist the urge to rush this step. The longer, slower cook creates those rich brown layers of sweetness.

Can I make this recipe vegetarian?

Definitely! Use vegetable stock instead of chicken or beef stock for a vegetarian-friendly version. The flavor will still be deeply satisfying thanks to the caramelized onions and cheeses.

What if I can’t find jumbo pasta shells?

If jumbo shells are unavailable, large manicotti tubes or large pasta shells work as great substitutes. Just adjust filling quantity as needed since sizes may vary slightly.

Can I prepare this dish ahead of time?

Yes, you can fully assemble the stuffed shells and store them in the refrigerator for up to 24 hours before baking. This makes it a fantastic make-ahead meal for busy days or entertaining guests.

Final Thoughts

I can’t recommend this French Onion Stuffed Shells Recipe enough for anyone who loves a dish that combines rich, comforting flavors with a bit of gourmet flair. It’s satisfying, approachable, and made with ingredients that are easy to find. Whether for a family dinner or a special occasion, this recipe will quickly become a beloved favorite. Give it a try and watch how this humble pasta transforms into something truly unforgettable.