Onion and Blue Cheese Tart

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 (translation: filling).

An onion and blue cheese tart cut into wedges with crispy onions scattered around it.

Don’t look at the long list of ingredients for this onion and blue cheese tart and think for a minute this is a difficult recipe. Because it’s not. It’s without a doubt one of the finest recipes on LC. I’ve made it for what seems like a ballroom full of guests and no one can ever seem to get enough.

I do have one small caveat, though. Bleu de Gex isn’t the easiest cheese to find. Do some investigative work in your local markets, because the difference it makes is noticeable. If you can’t find it, Stilton subs nicely.–David Leite

What is Bleu de Gex cheese?

Bleu de Gex cheese. Wondering what the heck is that? To be truthful, we asked ourselves the same thing the first time we encountered this recipe. More importantly, we also asked where can we find it? A scouring of New York City cheese shops left us empty-handed. (Well, not really, as we had a refrigerator full of some truly lovely cheeses…) If, like us, you can’t find the marvelous Bleu de Gex cheese, fret not. You can order it online. Or you can substitute Bleu d’Auvergne (another elusive cheese) or good old Stilton. Trust us, your tart will still be delicious, creamy, and requested time and again by friends and family.

Onion and Blue CheeseTart

  • Quick Glance
  • (5)
  • 30 M
  • 2 H, 15 M
  • Serves 8 to 10
5/5 - 5 reviews

Special Equipment: 10-inch (25-cm) tart pan with a removable bottom

Ingredients

  • For the onions
  • For the tart dough
  • For the filling
  • For the royale

Directions

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. Originally published April 18, 2005.

    *How to peel cipollini onions

    • The one downfall of cipollini onions is that if you don’t know how to properly peel them, this can take forever. We suggest you cut off the root end on each onion and then drop them in boiling water for 2 minutes. The peels will slip off much more readily than trying to wrestle with the papery skins. If you use this trick, shared with us by recipe tester Nadine Bonda, you may be able to decrease the time to roast the onions from 45 minutes to 30 minutes because they’re already partially cooked.

    David Says

    David Leite caricature

    Can we tawk? Just us two cooks? I know, I know. You look at a recipe like this, with all its components, and you think, "Have you been smoking more grass clippings, David?" Some of the ingredients (I'm talking to you, cipollini onions) can be hard to find. Then, of course, there's bleu de Gex. You may have never heard of it. And it ain't in your local supermarket. And what in the hell is a royale?!

    I hear you. But you've got to hear me: This recipe is worth every inch of exertion it may cause as well as the frustration and cost of finding bleu de Gex. Do you want to know how good this recipe is? There were times The One and I were on rocky ground--I mean that should-we-break-up?! ground--and this recipe was part of our reconciliation dinner. (We're still together after 27, years, so there's your proof!) And when I needed to impress a cookbook editor and potential TV producers, I whipped up this recipe. They left impressed. (Though I still don't have a TV show...)

    Please consider making this. It will challenge you, delight you, and make you fall off the dining chair--it's that good.

    Recipe Testers' Reviews

    This onion and blue cheese tart is well worth the time it takes. It's not only beautiful but it tastes divine. The filling is unlike a quiche filling in that it has more texture and taste with the addition of ricotta cheese and rème fraîche. The sweet taste of the lovely cipollini onions in combination with the bleu cheese is perfect. I served it for Sunday night dinner and it was a hit, described as "this is definitely a make again."

    The one downfall of cipollini onions is that if you don't know how to peel them, they can take forever. I cut off the root end on each then dropped them in boiling water for 2 minutes. This allowed me to pull off the skin in a much shorter time. Also, because the onions were now partially cooked, I was able to cut the time to roast the onions from 45 minutes to 30 minutes. Both of these steps were a plus in doing a multi-step dish.

    I used Bleu d'Auvergne cheese. I baked the completed tart for 30 minutes, but I did it on the middle rack in my oven to help it brown a little faster. It was perfect. It was nicely golden on the top and had a firm texture. I served it alone as dinner and found that it served two of us with an additional serving left for lunch tomorrow. 

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    Comments

    1. Oh, how we love this tart! I followed the recipe exactly the first time (ahem…as “exactly” as I could; I really NEEDED the crust to have a teensy bit of cornmeal in it the first go-round–delicious!) and made some modifications the second time around: I made 1 1/2 times the recipe for a 12″ tart pan, caramelized 2 1/4 lbs. of onions on the cooktop (time constraints–okay, a gorgeous So. Cal. day–precluded me from blanching/peeling/slaving over cippolini); I used fresh thyme–and lots of it–and just a bit of dried rosemary and sage; I substituted 1/2 cup whole-wheat flour in the crust for some extra chew; I used Gorgonzola (and went a bit light on it), and finally, I used heavy cream with a splash of 2% milk. Substitutions and subsequent reviews make me grumpy, but I’ve made it two times and can honestly say that either way (the labor/cost-intensive way OR the fast & cheap(er) way) this is one of the best foods that’s ever come out of my kitchen. It’s beautiful to look at and fabulous to serve to guests.

      1. Carissa, my head is spinning a bit from all the substituions and changes you made, but the bottom line is you loved the tart–and that’s all that matters to me! I’ve rediscovered this after a few years of not making it, and it’s in serious rotation at the moment.

    2. Delicious! I’ve made this twice, and both times found it to be nearly orgasmic. Couldn’t find Bleu de Gex, so I substituted Bleu d’Auvergne with fantastic results!

    3. Seriously, this is so amazing! I have made it a handful of times and it is super-easy. Give it a go! Thanks for this recipe, I love it.

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