Photo: Allie Chanthorn Reinmann
A classic tarte tatin is sweet, stuffed with apples, and requires a bit of fussing over a caramel sauce. It’s worth the effort when you’re looking for a sweet dessert, but you can also use the same technique for a dish that’s superbly savory. For a simple, shareable, and rather impressive plate, make a gorgonzola and caramelized onion tarte tatin.
What makes a tarte tatin a tarte tatin is a cap of puff pastry that, when plated, is flipped over and becomes the delicate, buttery, shattering crust underneath. The bottom is then unveiled as some sort of fruit smothered in a mahogany caramel sauce. We’re keeping everything here except the fruit. Instead, we’re caramelizing onions with butter to achieve a divine umami that tastes like we must have added 10 different ingredients when in reality it’s only the natural sugars from the onions developing their own flavors. A splash of balsamic adds sweetness, acidity, and a bit of smokiness, balancing out the salty richness of the onions. This base gives the impression of a delicious French onion soup. Once the gorgonzola and puff pastry are added, you can be confident the finished dish will be sublime.
Make sure to have a thawed sheet of puff pastry available. I usually grab a box from Trader Joes and thaw it in the fridge the night before. The package should have specified directions for thawing what brand of pastry you use. Unroll the pastry and, using a plate or a cake pan as a guide, cut the pastry into a circle the size of the pan you’ll be using. Cut some vents into the pastry, leave it on the paper backing, and put the entire thing back in the fridge or freezer. Slice four onions into long slices. I usually cut the onion in half, laterally. Put the onion cut-side down and slice it laterally, root to stem. The pieces should be about ¼-inch slices. Butter a cast iron skillet and lay slices around in a pattern you think you’ll like later when you flip it. If you’re worried about the onions sticking, you can lay a piece of parchment down first, then add the pieces of onion. Sprinkle a bit of brown sugar over the onions in the skillet. Toss the rest of the onions in a pot with butter and salt. Cook these down over medium low heat, covered, for about ten to fifteen minutes, stirring occasionally. The onions will begin to color and soften; as you stir, the color will disperse and get deeper. Keep the onions covered so they don’t dry out and burn. Set them aside to cool slightly, about five minutes.
Spread the caramelized onions on top of the decorative layer of onions in the skillet, then crumble gorgonzola over that. I add dry thyme on top, but you can use another herb you like. Take the puff pastry topper out of the fridge, and peel it off the paper. Quickly lay this over the onion tart in the skillet and press so it makes good contact with the onions. If the edges are a little wide, tuck them down into the tart. Bake this for about 30 minutes in a 400°F oven, until the top is lightly browned and the mixture is bubbling at the edges. Let it rest for a few minutes, then run a spoon around the edges, invert a plate over the top and, using an oven mitt, invert the pan over to flip out the tart. If you used parchment, you can peel it off now. If you did not, and any onion pieces stuck, use a fork or offset spatula to lift them out and replace them in the tart. No one will be the wiser.
Serve this tart in small slices, as an appetizer, or with a fresh, crisp salad, as the flavors of gorgonzola and caramelized onion are powerful and salty. The tart keeps in the fridge, covered, for about a day or two, but it’s much better if you eat it the first day.
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Gorgonzola & Caramelized Onion Tarte Tatin
Ingredients:
4 medium onions (sliced laterally into ¼-inch strips)4 tablespoons butter½ teaspoon salt1 tablespoon balsamic vinegar2 tablespoons of brown sugar3 tablespoons of gorgonzola crumbles1 teaspoon dry thyme1 sheet thawed puff pastryPreheat the oven to 400°F. Using a circular guide, cut the puff pastry into a circle that will fit into the top of your skillet (or cake pan, if you don’t have an oven-safe skillet). Dock the pastry and set it aside in the fridge or freezer. Use 2 tablespoons of the butter to grease the skillet and set a circle of parchment in the bottom if you want to be extra safe at the end.
Lay raw onion slices decoratively in the bottom of the skillet. Sprinkle the brown sugar over the onions in the pan. Put the rest of the onions in a pot with 2 tablespoons of butter, and the salt. Cook this down over medium-low heat until caramelized and set aside to cool slightly. Stir in the balsamic vinegar.
Spread the caramelized onion mixture evenly over the sliced onions in the skillet. Top with gorgonzola crumbles and thyme. Take the puff pastry out, and lay it on top of the onions in the skillet. If there is any overhang, tuck it down into the sides.
Bake at 400°F for 30 minutes, or until brown on top and bubbling around the sides. Let the skillet rest for a few minutes, but no more than five minutes or the caramel will stick. Flip the tart out onto a plate. Peel off the parchment paper, if used, and replace any rogue onions. Top with a small sprinkle of gorgonzola and serve while warm.
