Tarte Fine à l'Oignon et Chèvre
(tart feen ah loh-nyon eh shev-r)
Chapter 1 — Apéro & Hors d'Œuvres
If you have ever leaned against the pewter bar at Pastis or Balthazar, nursing a Sancerre while waiting on your steak frites, you know this tart. It is the quintessential bistro starter: deeply savory, unapologetically rich, and built on a foundation of uncompromising technique. Do not trust the cowards who tell you onions can caramelize in fifteen minutes; true brasserie depth demands an hour or more of low, slow heat in cast iron until those alliums collapse into sweet, mahogany jam. To keep the puff pastry shatteringly crisp under the weight of it all, we borrow a brilliant trick from French pastry chefs by blind-baking the dough trapped between two heavy baking sheets. It takes time, yes, but when you pull this out of the oven, your kitchen will smell exactly like Spring Street.
Before you start
Caramelize the onions in advance.
The onions can be cooked up to three days ahead of time and stored in an airtight container in the refrigerator.
Blend the cheese mixture early.
The goat cheese emulsion can be processed and kept in the fridge up to two days in advance; just let it soften slightly before spreading over the tart.
Ingredients
- yellow onions3 large
- extra-virgin olive oil2 tbsp
- unsalted European butter2 tbsp
- fresh thyme1 large sprig
- bay leaf1 large
- kosher salt3/4 tsp
- black pepper3/4 tsp
- Champagne vinegar or Sherry vinegar1 tbsp
- all-butter puff pastry1 sheet
- fresh goat cheese8 oz
- cream cheese4 oz
- extra-large egg1 large
- extra-large egg yolk1 large
- fresh nutmeg1 pinch
Method
- 01
Initiate the long cook for the onions.
Set a large cast iron skillet or heavy Dutch oven over medium-low heat. Add the olive oil and cultured butter, and once foaming, toss in the sliced onions, thyme sprig, bay leaf, 1/2 teaspoon of salt, and 1/2 teaspoon of pepper, stirring to coat evenly in the fat.
- 02
Caramelize the onions patiently for up to 90 minutes.
Do not rush this by cranking the heat. Stir every 5 to 10 minutes as the onions slowly release their moisture, eventually collapsing into a deeply sweet, dark mahogany jam that has reduced its original volume by nearly 75 percent.
- 03
Deglaze the skillet to balance the intense sweetness.
Remove the pan from the heat, discard the thyme and bay leaf, and stir in the vinegar. Scrape up every bit of browned fond from the bottom of the skillet, then transfer the onions to a bowl to cool completely.
- 04
Prepare the puff pastry for a double-pan blind bake.
Preheat your oven to 375°F (190°C). Roll the thawed pastry on a lightly floured surface to a 1/8-inch thickness, trim it into a 10-inch circle, and transfer it to a parchment-lined, heavy-duty baking sheet.
- 05
Weigh down the dough to keep it shatteringly thin.
Prick the dough all over with a fork to release steam, cover it with a second sheet of parchment paper, and lay a second heavy baking sheet directly on top of it to compress the pastry.
- 06
Blind-bake the pastry until pale and crisp.
Bake for 15 minutes, then carefully remove the top baking sheet and top layer of parchment. If the dough is still raw, let it bake uncovered for another 3 to 5 minutes until flat and cooked through like a cracker, then lower the oven temperature to 350°F (175°C).
- 07
Blend the stabilized cheese emulsion.
While the crust cools, combine the room-temperature goat cheese, cream cheese, whole egg, egg yolk, nutmeg, and the remaining 1/4 teaspoon of salt and pepper in a food processor, pulsing until the mixture is homogenous, silky, and devoid of lumps.
- 08
Assemble the final tart.
Spread the cooled, caramelized onions in a dense, even layer over the pre-baked crust, leaving a tiny 1/4-inch border at the edges. Carefully spread or dollop the goat cheese emulsion over the onions so it rests nicely on top.
- 09
Bake until the custard sets into a golden crown.
Return the tart to the 350°F (175°C) oven and bake for 15 to 20 minutes, or until the cheese mixture is slightly puffed, set, and beginning to crack or turn golden brown at the edges.
- 10
Cool briefly and serve.
Transfer the tart to a wire rack to cool for at least 10 minutes before slicing. Garnish with a few fresh thyme leaves and serve warm or at room temperature, ideally alongside a sharp salad of bitter greens dressed in a bracing Dijon vinaigrette.
Notes
The Emulsion Strategy.
Bistro kitchens blend fresh goat cheese with cream cheese and eggs because pure chèvre has a low moisture content and tends to break or weep under direct oven heat. This specific emulsion guarantees a lush, stable custard every time.
The Double-Plaque Technique.
Baking the puff pastry trapped between two heavy baking sheets forces the layers of butter and dough to fry in their own fat rather than puffing up uncontrollably. This creates an impermeable, crisp base that will not absorb the moisture of the onions.