SERVES 4 TO 6 · ACTIVE: 20 MIN · TOTAL: 2 HR 20 MIN
THIS CLASSIC TOMATO TART is an easy-to-assemble showstopper. Regular beefsteak tomatoes are great here—no need for pricier heirlooms since you’re baking them. Once you have this tart down, play around with different herbs and cheeses: Substitute sage for the marjoram and blue cheese for the Gruyère for a stronger flavor, or add a chopped anchovy to the herb-oil mixture before brushing it over the top. Serve the tart warm just after baking it, or make it a day ahead, refrigerate it, and bring it to room temperature before serving.
1 Savory Tart Crust (here)
2 tablespoons plus 2 teaspoons extra-virgin olive oil
4 large shallots, thinly sliced
2 tablespoons chopped fresh chives
Fine sea salt and freshly ground black pepper
12 ounces aged Gruyère cheese; 8 ounces sliced, 4 ounces coarsely grated
2 tablespoons smooth Dijon mustard
2 tablespoons coarse-ground mustard
2 pounds ripe large red and yellow tomatoes, stems removed and cut into ¼-inch-thick slices
3 tablespoons chopped fresh marjoram
Preheat the oven to 350°F. Butter and flour a 9 x 13 x 1-inch rectangular tart pan or a 9½-inch round tart pan.
On a lightly floured surface, roll out the dough into a rectangle or circle (depending on the pan you’re using) about ⅛ inch thick and a bit bigger than the pan you’re using. Transfer the dough to the pan, letting it hang slightly over the edges. Trim off the excess dough and prick holes all over with a fork. Bake until the dough just starts to turn light brown, about 20 minutes. Remove from the oven and let cool for a few minutes.
In a large sauté pan over medium-low heat, heat 2 teaspoons of the olive oil and cook the shallots until they’re soft and translucent, about 10 minutes. Stir in the chives, a large pinch of salt, and four turns of black pepper and remove from the heat.
Evenly layer the sliced cheese to cover the bottom of the tart dough. Spread both mustards over the cheese and evenly distribute the shallots on top of the mustard. Finally, layer the sliced tomatoes by alternating a row of red tomatoes with a row of yellow tomatoes, overlapping each slice by about ½ inch. If using a round pan, start from the outside, working in. Bake until the crust is golden brown and the tomatoes are soft, about 40 minutes.
Combine the remaining 2 tablespoons olive oil with the marjoram and a pinch of salt. Gently brush the marjoram mixture on the tomatoes with a pastry brush. Sprinkle the grated cheese evenly over the tomatoes. Bake for another 20 minutes or so, until the crust is a nice golden brown, the cheese on top is melted, and the tomatoes are soft. Let cool for 10 to 15 minutes before serving.