The Ultimate Onion and Blue Cheese Tart: A Gourmet Savory Pie Recipe

Prepare to be enchanted by this exquisite Onion and Blue Cheese Tart, a savory pie that transcends expectations. Despite what might appear to be a comprehensive ingredient list, this recipe is surprisingly straightforward and consistently delivers a show-stopping result. It combines the sweet, mellow flavors of roasted cipollini or pearl onions with a rich, creamy ricotta base and a luxurious blue cheese “royale” – a velvety custard-like filling that binds all the flavors together in perfect harmony. This tart has earned its reputation as one of the finest recipes, captivating guests and leaving them craving more.

A note from David Leite: “This tart is truly a masterpiece. While the ingredient list might seem long, don’t be intimidated; it’s genuinely one of the easiest and most rewarding recipes we’ve shared. I’ve served it to countless guests, and it’s always met with rave reviews. One small piece of advice, though: Bleu de Gex cheese, while transformative, can be a bit elusive. I highly recommend seeking it out in your local gourmet markets, as its unique flavor profile makes a noticeable difference. If you’re unable to find it, a good quality Stilton makes an excellent, readily available substitute.”

Why This Onion and Blue Cheese Tart Will Become Your New Favorite

This isn’t just any savory pie; it’s a symphony of textures and flavors. The natural sweetness of slowly roasted onions caramelized to perfection, the subtle tang and creamy texture of the ricotta filling, and the pungent, sophisticated notes of blue cheese all encased in a buttery, flaky pastry crust. It’s a dish that feels both rustic and refined, perfect for any occasion from a casual brunch to an elegant dinner party. Its versatility means it can shine as a gourmet appetizer, a light lunch with a side salad, or even a sophisticated main course.

Unveiling the Star Ingredients

The Sweetness of Roasted Onions

The foundation of this tart’s incredible flavor lies in the onions. We use cipollini, boiling, or large pearl onions, which become incredibly sweet and tender when roasted. This roasting process is crucial; it mellows their sharpness and concentrates their sugars, transforming them into soft, golden jewels. Infused with aromatic herbs like fresh rosemary, finely sliced sage, and fragrant thyme, these onions don’t just add a layer of flavor; they become a star ingredient in their own right, offering a delightful counterpoint to the rich cheeses.

The Rich Ricotta Filling: A Creamy Foundation

Beneath the roasted onions and creamy royale lies a layer of luxurious whole-milk ricotta, blended smoothly with a large egg yolk and a touch of extra-virgin olive oil. This mixture creates a foundational creaminess and adds a delicate tanginess, especially when stirred with crème fraîche. This base prevents the tart from being overly dense and provides a beautiful, soft texture that complements the other, bolder flavors.

The Blue Cheese Royale: A Decadent Finish

The “royale” refers to a classic French custard mixture, and in this tart, it’s elevated with the distinct flavor of blue cheese. Made with a blend of egg, flour, heavy cream, whole milk, and more crème fraîche, this rich custard envelops the roasted onions and blue cheese, creating a melt-in-your-mouth experience. It acts as the binder, ensuring every slice holds its form while delivering an unbelievably silky texture that enhances the overall richness and complexity of the tart.

Choosing Your Blue Cheese: Bleu de Gex and Its Alternatives

What Makes Bleu de Gex Special?

Bleu de Gex is a semi-hard blue cheese originating from the Jura Mountains in France, celebrated for its mild, earthy, and slightly sweet flavor profile. Unlike some more assertive blue cheeses, Bleu de Gex offers a delicate blue veining and a creamy texture that melts beautifully, making it an ideal choice for this tart. Its nuanced taste allows the sweetness of the roasted onions to shine through while providing that unmistakable blue cheese depth. Finding this artisanal cheese might require a visit to specialty cheese shops or an online order, but many enthusiasts believe its unique character is well worth the effort.

Excellent Substitutions for Bleu de Gex

If your quest for Bleu de Gex proves challenging, fret not! Your tart will still be exceptionally delicious with a suitable substitute. Good old Stilton is a fantastic alternative, offering a robust, tangy flavor and a crumbly yet creamy texture that holds up well in baking. Another excellent option, though sometimes equally elusive, is Bleu d’Auvergne, a French blue cheese known for its intense aroma and creamy consistency. Whichever blue cheese you choose, ensure it’s of high quality to achieve the best flavor. And if you happen to have any leftover blue cheese, consider using it to make a divine broccoli and blue cheese gratin!

Crafting the Perfect Flaky Tart Crust

A truly exceptional tart begins with an exceptional crust. This recipe calls for a classic all-butter tart dough, which, when prepared correctly, yields a wonderfully flaky and tender base that complements the rich filling without overpowering it. The key to success lies in keeping the butter very cold and working the dough minimally. Using a food processor makes quick work of incorporating the butter into the flour until it resembles small peas, ensuring pockets of butter that create flakiness when baked. A gradual addition of ice water brings the dough together, forming a pliable disc that’s easy to roll out. Chilling the dough before baking is a crucial step that helps prevent shrinkage and ensures a perfectly crisp crust.

Onion and Blue Cheese Tart

Rated 5 out of 5 stars by 10 users

This onion and blue cheese tart is a savory pie made with roasted cipollini or pearl onions, a rich ricotta filling, and a creamy blue-cheese royale.

By David Leite

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Course: Appetizers

Cuisine: French

Servings: 8 to 10 slices

Calories: 534 kcal per slice

Prep Time: 30 minutes

Cook Time: 1 hour 45 minutes

Total Time: 2 hours 15 minutes

Equipment

• 10-inch (25-cm) tart pan with a removable bottom

Ingredients

For the onions

• 1 1/2 pounds cipollini, boiling, or large pearl onions, peeled* (see *How to peel cipollini onions below) and quartered
• 1/4 cup extra-virgin olive oil
• 1/4 cup loosely packed rosemary leaves
• 1 tablespoon finely sliced sage leaves
• 1 tablespoon thyme leaves
• 1 teaspoon Kosher salt

For the tart dough

• 2 cups all-purpose flour, plus more for the work surface
• 1/4 teaspoon Kosher salt
• 12 tablespoons (6 oz) cold unsalted butter, cut into 1/2-inch (12-mm) cubes
• 3 to 5 tablespoons ice water

For the filling

• 1/2 cup whole-milk ricotta, drained if wet
• 1 large egg yolk
• 1 tablespoon extra-virgin olive oil
• 1/4 cup crème fraîche
• Pinch of kosher salt and freshly ground black pepper

For the royale

• 1 large egg
• 1 teaspoon all-purpose flour
• Pinch kosher salt
• 1/4 cup heavy cream
• 1/4 cup whole milk
• 1 tablespoon crème fraîche
• 1/2 pound Bleu de Gex, rind removed and cut into 1/4-inch slices, (you can substitute Stilton or Bleu d’Auvergne)

Instructions

Prep the onions

• Preheat the oven to 350°F (175C°).
• In a small bowl, toss together the onions, olive oil, rosemary, sage, thyme, salt, and pepper. Spread the mixture in a single layer on a rimmed baking sheet and roast until the onions are softened and begin to color but still hold their shape, 45 minutes.

  ☞ TESTER TIP: If you used our nifty peeling trick for cipollini onions found beneath the recipe, you may find you can reduce the roasting time by as much as 15 minutes since the onions have been partially cooked.

• Place the baking sheet on a wire rack to cool. Increase the oven temperature to 375°F (190°C) and adjust the oven rack to the middle position.

Make the tart dough

• Dump the flour and salt in the bowl of a food processor and pulse to combine. Add the butter and pulse until the mixture resembles small peas, about 10 one-second pulses. While pulsing the mixer, drizzle 3 tablespoons ice water through the feed tube until the dough starts to come together. If the dough isn’t coming together, add the remaining water, 1 tablespoon at a time. Don’t overmix the dough.
• Transfer the dough to a lightly floured work surface and form it into a disc with your hands. Roll out the dough into a 13-inch circle, then ease it into a 10-inch tart pan, fitting it snugly against the sides and bottom, and trim the excess. Prick the bottom of the tart with a fork and refrigerate for 30 minutes.

Make the filling

• In a small bowl, whisk the ricotta, egg yolk, and olive oil until smooth. Stir in the crème fraîche and season with salt and pepper.

Make the royale

• Whisk the egg, flour, and salt in a small bowl. Heat the cream and milk in a small saucepan until hot but not boiling, then slowly add it to the egg and flour mixture, whisking until smooth. Stir in the crème fraîche.

Assemble the tart

• Spread the filling evenly in the tart shell. Scatter 3/4 of the onions in the tart shell and drizzle with the royale. Arrange the slices of cheese on top. Dot with the remaining onions.
• Bake the tart for 30 minutes, rotating it 180° after 15 minutes.
• Loosely cover the tart with foil and bake for another 15 minutes. If the pastry needs more color, increase the heat to 400°F (200°C), uncover the tart, and bake for 10 to 15 more minutes.
• Cool the tart in its pan on a wire rack for at least 5 minutes. Slice and serve.

Notes

*How To Peel Cipollini Onions

Peeling cipollini onions can be a tedious task, but we have a secret trick to make it much easier! Simply cut off the root end of each onion, then drop them into boiling water for just 2 minutes. The skins will then slip off with remarkable ease. This ingenious method, shared by our recipe tester Nadine Bonda, not only saves time but also partially cooks the onions, potentially allowing you to reduce their roasting time from 45 minutes to about 30 minutes.

An LC Original

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Nutrition Facts (per slice)

• Serving: 1 slice
• Calories: 534 kcal
• Carbohydrates: 35 g
• Protein: 12 g
• Fat: 39 g
• Saturated Fat: 18 g
• Monounsaturated Fat: 15 g
• Trans Fat: 1 g
• Cholesterol: 132 mg
• Sodium: 429 mg
• Fiber: 3 g
• Sugar: 5 g

Nutrition information is automatically calculated, so should only be used as an approximation.

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Expert Tips for Tart Perfection

To ensure your Onion and Blue Cheese Tart turns out perfectly every time, keep these expert tips in mind. Firstly, when preparing the dough, avoid overmixing. Overworking the gluten will result in a tough crust, so pulse just until the ingredients come together. Secondly, the chilling steps for the dough are essential; they help the butter firm up, preventing the crust from shrinking in the oven and ensuring a delightfully flaky texture. Thirdly, monitor your onions during roasting; you want them softened and slightly golden, but not overly browned or mushy. Finally, ovens can vary, so keep an eye on your tart during the final baking stages. Adjust the temperature and baking time as needed to achieve a beautifully golden crust and a firm, set filling.

Serving Suggestions for Your Savory Masterpiece

This savory tart is incredibly versatile and pairs wonderfully with various accompaniments. For a complete meal, serve warm slices alongside a simple, crisp green salad dressed with a light vinaigrette. It’s also an ideal centerpiece for a brunch spread, a sophisticated addition to a lunch menu, or an impressive appetizer when cut into smaller wedges. Consider complementing its rich flavors with a glass of crisp Sauvignon Blanc or a light-bodied Pinot Noir. Whether served warm from the oven or at room temperature, this tart promises to be a memorable culinary experience.

Experience Culinary Excellence at Home

This Onion and Blue Cheese Tart is more than just a recipe; it’s an invitation to create something truly special in your kitchen. With its harmonious blend of sweet, savory, and tangy notes, and its elegant presentation, it promises to impress anyone who takes a bite. Whether you’re an experienced baker or a novice in the kitchen, follow these clear steps and soon you’ll be enjoying a tart that tastes like it came straight from a gourmet French patisserie. Don’t hesitate to give this unforgettable savory pie a try – you won’t regret it!

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