Caramelized onion and Gruyère galette distills the flavors of French onion soup into a lushly cheesy galette with a crisp, flavorful rye crust. A spectacular main or side that is an absolute showstopper.
I love to serve this as a hearty fall or winter dinner alongside a fresh, green salad simply dressed with some red wine vinegar and good olive oil. Bon appétit.–Taylor Harbin
WHAT KIND OF ONIONS ARE BEST FOR CARAMELIZING?
Taylor Harbin recommends yellow or white onions. We agree with that, but if you want a little more in-depth info about onions, we’ve got your back. For French onion soup, which this galette is based on, the onions are often caramelized until they’re quite, quite dark and any onion you have on hand can be used.
But here’s the thing. Onions have different tastes and will give you a different finish. Sweet onions are mellow and have more sugar, making them a little easier to caramelize. Yellow onions are a little sharper and brighter, with just a bit of sweetness. Red onions are sharp and deep, with a little bitterness; in this recipe, they’ll also be quite a darker color than the other types.
☞ Table of Contents
Caramelized Onion and Gruyère Galette
For the rye dough
- 2 large egg yolks
- 2 teaspoons apple cider vinegar
- 8 to 10 tablespoons ice water or more, divided
- 2 cups all-purpose flour
- 2 cups rye flour
- 2 teaspoons sea salt
- 2 sticks (8 oz) unsalted butter cold and cut into 1/2-inch (1.3-cm) cubes
For the caramelized onion and gruyère galette
- 1 tablespoon olive oil
- 1 tablespoon (1/2 oz) unsalted butter at room temperature
- 1 large (8 oz) white or yellow onion cut into 1/4-inch (6-mm) thick rounds with layers intact
- 3 whole sprigs fresh thyme plus 5 sprigs with leaves removed from stems and finely chopped divided
- 3 whole sprigs fresh rosemary plus 2 sprigs with leaves removed from stems and finely chopped divided
- Sea salt and freshly ground black pepper
- 1/2 cup dry red wine
- 1/4 cup store-bought or homemade beef broth
- 4 ounces Gruyère cheese grated
- 1 ounce Parmigiano-Reggiano cheese grated
- 1/2 recipe Rye dough patted into a disc
- 1 large egg lightly beaten
- Flaky salt
Make the rye dough
- In a small bowl, mix together egg yolks, vinegar, and 8 tablespoons of ice water.
- In a large bowl, combine the all-purpose and rye flours and salt. Add the butter, and toss to coat. Using your hands, pinch the pieces of butter between your thumbs and pointer fingers to flatten them into thin shards of butter, toss to fully coat in flour. Continue until all the butter has been flattened, working quickly to prevent butter from getting too warm.
- Pour the egg mixture over the flour mixture, toss with your hands to incorporate the ingredients.
- Drizzle over the remaining 1 to 2 tablespoons of ice water as needed, a little at a time, just until the dough comes together and is no longer dry and crumbly. You may not need all of the remaining 2 tablespoons, depending on the humidity of the day, or you may need a bit more. You want to add just enough water for the dough to feel firmly held together and smooth rather than dry and crumbly, but not so much that it’s soft, wet, and sticky to the touch.
- Pat dough out into a disc about 1-inch (2.5 cm) thick. Using a bench scraper or knife, slice disc into quarters and stack pieces on top of one another. Gently pat out the dough with your hands into a disc about 1-inch (2.5 cm) thick. Repeat the cutting and stacking once more. This process is going to give you all those flaky layers.
- Divide dough into 2 discs, wrap tightly in plastic wrap and chill for at least 2 hours or, ideally, overnight. Allow dough to sit at room temperature for a few minutes to soften slightly before rolling it out. You only need one disc for this recipe, so the remaining disc can be frozen for future pie or galette cravings.
Make the caramelized onion and gruyère galette
- Heat a large cast-iron skillet over medium-low heat. Add olive oil and butter to the skillet. Once the butter has melted, add the onion rounds in a single layer and tuck the whole sprigs of rosemary and thyme into the skillet. Season the onion with salt and pepper and let cook, undisturbed, until the onion is caramelized and golden brown on the bottom, 10 to 15 minutes.
- Using a small offset spatula, carefully flip, being careful to keep the onions in one piece, season with salt and pepper again, and cook until there’s a caramelized layer on the other side, 10 to 15 minutes. Should you have a few layers of onion slip around a bit, no matter. Just tuck them in their round as best you can.
- Add wine and beef broth, and cook until the liquid has reduced and is thick and syrupy, 8 to 10 minutes. Remove skillet from heat and let onions cool completely.
- In a small bowl, toss the Gruyère and Parmigiano cheeses together with the chopped thyme and rosemary.
- Line a rimmed baking sheet with parchment paper. On a well-floured surface, roll the dough out into a large circle 1/4- to 1/8-inch (6 to 3 mm) thick and 10- to 12-inches (25 to 30 cm) in diameter. Transfer dough to the prepared baking sheet.
- Sprinkle cheese mixture on dough, leaving about a 2-inch (5-cm) border. Gently arrange the onion rounds over the cheese mixture in a single layer. Spoon the syrupy pan juices over the onions.
- Fold the sides of the dough up and over the edge of the filling, overlapping it onto itself to create a pleated pattern. Freeze the galette on the baking sheet for 30 minutes.
- Meanwhile, preheat oven to 400°F (204°C).
- Brush the sides of the dough with beaten egg, and sprinkle with flaky salt. Bake until the crust is golden brown and the filling is bubbling, 30 to 35 minutes. Cool the galette for a few minutes before serving.
Recipe Testers’ Reviews
This recipe is a showstopper! The caramelized onion and Gruyère galette is an umami-filled riff on French onion soup worthy of serving to company. The rings of caramelized onions are beautifully nestled on a bed of melted Gruyère and Parmigiano cheeses all held together by a savory, flaky crust. This versatile dish would be just as delicious for brunch as it would for dinner.
The rye pastry dough takes just a few minutes to assemble the day before you want to make the galette. Flipping the onions over in the pan was tricky but not impossible. I did have to coax a few of the rings back into place but you would never know looking at the finished product. The dough needs to sit out a couple of minutes before you can roll it out. I rolled the dough into a 12-inch circle which then turned into a 10-inch galette.
As the main course, served with a salad, it yielded 4 servings. As a side dish, it would be easy to get 5-6 servings from it. It yielded a tender, flaky crust that was easy to cut and serve.
This caramelized onion and Gruyère galette is a bit of a time commitment (more than a typical galette) but oh, what a showstopper in terms of both flavor and presentation. This would make a fabulous holiday menu addition, especially since it can be made in multiples to the point of freezing, then they could be baked off all at once.
The rye crust is one of the crispiest, flakiest, and most delicious I’ve ever made. The slight earthiness of the rye beautifully complements the filling. After baking, I topped it with some minced thyme, rosemary, and allium blossoms for color. I was thrilled that it made two discs because I got to turn the other one into a stunningly beautiful heirloom tomato tart.
I blind-baked the 2nd crust in a 10-inch tart pan. After freezing it for 15 minutes, filling it with pie weights, and baking, it perfectly held its shape from the tart pan and was shatteringly crisp and flaky! I could see this crust playing a supporting role in so many savory pies and tarts.
This caramelized onion and Gruyère galette recipe produces a heavenly, light, rich galette that melts in the mouth. Apologies for the pedestrian turn of phrase, but I cannot find the right superlatives to convey how delicious this tart was. I knew it was worthy of a TC recommendation on the first bite.
I would be less concerned about having perfect onion rounds and focus more on producing a good batch of caramelized onions. The aesthetics of the tart wouldn’t suffer if they fail to remain whole. I followed the instructions but ultimately went for the color and texture, bidding au revoir to the perfect shape. The finished tart looked lovely and tasted even better.
The rye crust is one of the best pie crusts I’ve ever produced. I made a full batch of the pie crust but used the food processor to produce the dough. I typically use the food processor to make pie dough. I can do it by hand, but as a matter of preference, I like the results I get from the food processor. I cubed the butter and chilled it for ten minutes in the freezer. The dough chilled overnight in the fridge. The dough was supple and easy to roll out. I think it would work well for savory and sweet galettes.
Originally published on October 12, 2021