Heirloom Tomato & Gruyere Tart
Pulse the flour, salt and cold butter into crumbs, add the egg yolks and water to form a dough, and chill for 30 minutes. Pulse the parsley, basil, dill and garlic with the olive oil and spread it over the tomato slices. Roll the dough ¼-inch thick, bake under foil and pie weights at 400° for 15 minutes, remove them, and bake 8 to 10 minutes more until golden. Brush with mustard, layer half the Gruyere, the tomatoes, the remaining Gruyere and the Parmesan, and bake at 375° until melted.
For a few short weeks each summer, heirloom tomatoes arrive in their impossible colors — deep purples, streaked golds, ribboned reds — and a good cook builds a dish to hold them at their peak. This tart is that dish: a buttery crust, a bed of nutty Gruyère, and overlapping slices of marinated heirlooms baked until the cheese bubbles. It is the taste of the season, framed in pastry.
The All-Butter Crust and the Blind Bake
A tart is only as good as its base, and this one is all butter. Pulse cold, cubed butter into the flour just until it forms pea-sized crumbs, bind it with egg yolks and ice water, and chill the disk to relax the gluten and firm the fat — the two things that guarantee a flaky, tender crust. Then blind-bake it with foil and weights until golden and set, so the pastry is already crisp before a single tomato goes on.
The Dijon Moisture Barrier
Tomatoes are gloriously juicy, which is a problem for pastry — and the fix is a thin brush of Dijon mustard across the cooled, blind-baked crust. The mustard forms a protective, flavorful barrier that keeps the tomato juices from soaking in and turning the base soggy, while a scatter of Gruyère beneath the fruit adds another seal. Arrange the herb-marinated slices tightly, top with more Gruyère and Parmesan, and bake until molten and golden.
Heirloom Tomato & Gruyere Tart
Ingredients
Method
- Place the flour and salt into the bowl of a food processor. Add the chilled butter pieces. Pulse to form crumbs.
- Add the egg yolks and pulse to combine. Add some of the water and pulse to form a dough. Add more water as needed.
- Pour out the dough to your lightly floured work surface. Pat the dough into a disk, wrap in plastic, and chill in the fridge for 30 minutes.
- Place the slices of tomatoes onto a platter or into a shallow bowl.
- Place the parsley, basil, dill and garlic into the bowl of a food processor. Pulse to finely chop the herbs. Season with salt and pepper.
- With the machine running, slowly pour in the olive oil. Spread this herb-olive oil over the tomatoes.
- Preheat the oven to 400°. Pull the dough from the fridge and place between two sheets of plastic wrap. Roll out the dough to about ¼-inch thick. It’s your choice to shape the dough as you wish, either a rectangle or circle. Use the plastic wrap to transfer the dough to a baking sheet. Remove the wrap.
- Use your finger to form a crust around the edges.
- Spray a sheet of aluminum foil with vegetable oil spray (so it doesn’t stick) and gently push it down and over the dough. Use pie weights or dried beans to hold the foil in place. Bake for 15 minutes.
- Remove the foil (with the pie weights) and bake until golden, about 8 to 10 minutes more. If the pastry puffs up during baking, use a fork to gently pierce the bubbles. You want it to be a flat tart. Remove the tart from the oven and cool to room temperature.
- Lower the oven temperature to 375°.
- Brush the mustard onto the bottom of the tart.
- Place half of the Gruyere cheese over the mustard.
- Arrange the tomato slices over the cheese. Top the tomatoes with the remaining Gruyere and the Parmesan cheeses.
- Place the tart back into the oven and bake until the cheese is melted, about 20 to 30 minutes. Serve the tart warm from the oven or at room temperature.
The Heart of the Table
To serve this tart is to serve the summer itself, caught at the one moment the tomatoes are perfect. There is a deep, seasonal generosity in that — in taking the fleeting best of the garden and turning it into something beautiful enough to set at the center of a table. It is the kind of dish that makes a warm evening feel like an occasion worth remembering.
The Art of the Host
A food processor earns its keep twice here — once for cutting the butter into the crust, and again for whirling the herb oil that marinates the tomatoes. A baking sheet is all the crust needs, with the edge formed by hand for a rustic free-form tart. Keep pie weights or dried beans on hand for the blind bake; they're what keep the pastry flat and even.
Neighborly Grace
- The Preparation: Blind-bake the all-butter crust and brush it with Dijon before the tomatoes touch it — that mustard layer keeps the pastry crisp beneath the juicy heirlooms. Spread the herb oil over the tomato slices, then layer them over the Gruyere so every bite carries the herbs.
- The Pour: A crisp rosé or a Sauvignon Blanc suits a summer tart. For a non-alcoholic option, a cucumber-basil cooler or a sparkling lemonade keeps it garden-fresh.
- The Vibe: This is high summer on a plate — layered, jewel-toned, and rustic-elegant, best served just warm or at room temperature on a slow afternoon.