French Onion Stuffed Shells Recipe
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French onion soup is one of the most beloved savory starters out there, and it relies on a relatively simple combination of ingredients to achieve great flavor heights. This French onion stuffed shells recipe takes things a step further, combining brothy caramelized onions with delicate shell pasta, all topped off with a mix of cheeses to pull off a main dish based on the classic starter. Each shell features a creamy, cheesy mixture of ricotta, Gruyère, and parmesan cheeses, all nestled into a skillet base of caramelized onions in a gravy-like sauce before baking. A simple breadcrumb topping provides a little textural contrast, evoking a similar feel to a bread-topped bowl of soup you might enjoy in a restaurant.
To make this dish a little more busy weeknight-friendly, I'll often prep the onions over the weekend to get a head start. Stuffed shells are a little more labor-intensive than your average pasta dish, but it's well worth the extra effort when you want something a little more elevated or special.
Gather the ingredients for French onion stuffed shells
To make this recipe, start with four sweet onions (yellow onions will also work), garlic, and fresh parsley. You'll also need unsalted butter, ricotta cheese, eggs, Gruyère cheese, parmesan cheese, and heavy cream. Next, reach for jumbo pasta shells, vegetable broth, and breadcrumbs (or make your own easy breadcrumbs instead). Check your pantry for all-purpose flour, dried thyme, salt, and pepper.
Step 1: Melt butter in skillet
Melt the butter in a large oven-safe skillet over medium-low heat.
Step 2: Cook the onions
Add the onions, 1 teaspoon salt, ½ teaspoon pepper, and ½ teaspoon thyme. Cook for about 45 minutes, stirring occasionally to prevent burning, until the onions are golden brown.
Step 3: Stir in the garlic
When the onions are golden, stir in the garlic and cook for 2 minutes more. Then, turn off the heat and leave the onions in the pan.
Step 4: Bring water to a boil
While the onions cook, bring a large pot of salted water to a boil.
Step 5: Cook the pasta shells
Cook the shells for 2 minutes less than the package instructions call for, until bendable but still firm in the center.
Step 6: Cool the shells
Drain and spread the shells in a single layer on a baking sheet to cool.
Step 7: Preheat the oven
Preheat the oven to 400 F.
Step 8: Prepare the cheesy shell filling
Stir together the ricotta, egg, 1 cup Gruyère, half of the parmesan, and the remaining salt, pepper, and thyme in a large bowl.
Step 9: Add some caramelized onions to cheese mixture
Stir ½ cup of the caramelized onions into the ricotta mixture.
Step 10: Stuff the shells
Fill each shell with the ricotta mixture, stuffing them full but not overflowing.
Step 11: Sprinkle flour over remaining onions in skillet
Turn the heat to medium-low under the remaining onions in the pan and sprinkle in the flour. Cook, stirring frequently, for 1 to 2 minutes.
Step 12: Pour in broth
Add the broth and cook for 5 to 6 minutes, stirring frequently, until the sauce thickens.
Step 13: Stir in the cream
Stir in the cream, then turn off the heat.
Step 14: Place the shells in the skillet
Nestle the shells open side up in the sauce.
Step 15: Top the shells with cheese and breadcrumbs
Top the shells with the breadcrumbs, remaining Gruyère, and remaining parmesan.
Step 16: Bake the stuffed shells
Bake until the cheese is browned and the sauce bubbles around the edges, 20 to 25 minutes.
Step 17: Top the stuffed shells with parsley before serving
Sprinkle the shells with parsley before serving.
What to serve with French onion stuffed shells
French Onion Stuffed Shells Recipe
Inspired by classic French onion soup, this stuffed shells recipe features caramelized onions, a savory, brothy sauce, and lots of creamy, melty cheese.
Ingredients
- 2 tablespoons unsalted butter
- 4 sweet onions, thinly sliced
- 1 ½ teaspoons salt, divided
- ¾ teaspoon black pepper, divided
- ¾ teaspoon dried thyme, divided
- 2 garlic cloves, minced
- 8 ounces jumbo pasta shells (about 24 shells)
- 2 cups ricotta cheese
- 1 egg
- 2 cups grated Gruyère cheese, divided
- ⅓ cup grated parmesan cheese, divided
- 1 tablespoon all-purpose flour
- 1 ½ cups vegetable broth
- ⅓ cup heavy cream
- ¼ cup breadcrumbs
- 2 tablespoons chopped fresh parsley
Directions
- Melt the butter in a large oven-safe skillet over medium-low heat.
- Add the onions, 1 teaspoon salt, ½ teaspoon pepper, and ½ teaspoon thyme. Cook for about 45 minutes, stirring occasionally to prevent burning, until the onions are golden brown.
- When the onions are golden, stir in the garlic and cook for 2 minutes more. Then, turn off the heat and leave the onions in the pan.
- While the onions cook, bring a large pot of salted water to a boil.
- Cook the shells for 2 minutes less than the package instructions call for, until bendable but still firm in the center.
- Drain and spread the shells in a single layer on a baking sheet to cool.
- Preheat the oven to 400 F.
- Stir together the ricotta, egg, 1 cup Gruyère, half of the parmesan, and the remaining salt, pepper, and thyme in a large bowl.
- Stir ½ cup of the caramelized onions into the ricotta mixture.
- Fill each shell with the ricotta mixture, stuffing them full but not overflowing.
- Turn the heat to medium-low under the remaining onions in the pan and sprinkle in the flour. Cook, stirring frequently, for 1 to 2 minutes.
- Add the broth and cook for 5 to 6 minutes, stirring frequently, until the sauce thickens.
- Stir in the cream, then turn off the heat.
- Nestle the shells open side up in the sauce.
- Top the shells with the breadcrumbs, remaining Gruyère, and remaining parmesan.
- Bake until the cheese is browned and the sauce bubbles around the edges, 20 to 25 minutes.
- Sprinkle the shells with parsley before serving.
Are there any shortcuts I can take when making these stuffed shells?
If you want to shorten the time it takes to make this dish, here are a few pointers. Slicing the onions can take some time by hand, but certain tools can speed up the process. If you have a mandoline, you can use that to quickly and evenly slice the onions. Peel the onions and cut in half lengthwise, then slice to ⅛-inch thickness on the mandoline using a cut resistant glove or a hand guard. Alternatively, you could use a food processor with the slicing blade for a super-speedy option. If you have any time to prep the night before you plan to make the dish, you can easily slice the onions to get a small step out of the way. You can also fully prepare the caramelized onions, then let them cool before refrigerating for upwards of two days. When you're ready to use them, pull them from the fridge and proceed with the recipe — you don't even need to heat the onions up before proceeding, since they'll cook with the rest of the dish in the oven.
Another shortcut is to use pre-grated cheese instead of grating it yourself. If you have a hard time finding pre-grated Gruyère, try mozzarella or Swiss for a similar effect. If stuffing the shells is too tedious, cook your favorite type of pasta instead and mix it with the ricotta mixture. Then, transfer the pasta to the skillet, top with the caramelized onions and cheese, and bake for a slightly easier rendition.
Can I make these stuffed shells in a glass baking dish instead of a skillet?
If you don't have a large enough skillet or one that can safely go in the oven, then you can use a glass baking dish for the shells instead. The caramelizing step can be done in a skillet or a saucepan, or you can actually caramelize the onions in the oven. To do this, toss the onions with melted butter and a pinch of salt, then place in a glass baking dish. You'll want to roast the onions at 400 F for about an hour, stirring every 15 minutes. If the pan gets dry, splash in some water or broth. Oven-cooked onions will be less jammy and have more of a roasted feel, but the overall flavor profile will remain the same. Then
Regardless of which way you choose to caramelize the onions, you can still cook the stuffed shells in a glass baking dish. The temperature and cook time will remain the same. Note that the top cheesy layer of the shells may cook more quickly in a glass dish, so check on them often to avoid burning. You can also tent the dish with foil towards the end of the bake time to avoid over-browning the top.