SERVES 6 TO 8
Either yellow or white onions work well in this recipe, but stay away from sweet onions, such as Vidalias, which will make the tart watery. Use a 9-inch tinned-steel tart pan; click here for our recommended brand. This tart can be served hot or at room temperature and pairs well with a green salad as a main course.
CRUST |
|
1¼ |
cups (6¼ ounces) unbleached all-purpose flour |
1 |
tablespoon sugar |
½ |
teaspoon table salt |
8 |
tablespoons (1 stick) unsalted butter, cut into ½-inch cubes and chilled |
2–3 |
tablespoons ice water |
FILLING |
|
4 |
ounces bacon (about 4 slices), halved lengthwise and cut crosswise into ¼-inch pieces |
Vegetable oil, as needed |
|
1½ |
pounds onions (about 3 medium), halved pole to pole and cut crosswise into ¼-inch slices (about 6 cups; see note) |
¾ |
teaspoon table salt |
1 |
sprig fresh thyme |
2 |
large eggs |
½ |
cup half-and-half |
¼ |
teaspoon ground black pepper |
1. FOR THE CRUST: Spray a 9-inch tart pan with a removable bottom with vegetable oil spray; set aside. Pulse the flour, sugar, and salt together in a food processor until combined, about 4 pulses. Scatter the butter pieces over the flour mixture and pulse until the mixture resembles coarse sand, about 15 pulses. Add 2 tablespoons of the ice water and continue to process until large clumps of dough form and no powdery bits remain, about 5 seconds. If the dough doesn’t clump, add the remaining 1 tablespoon water and pulse to incorporate, about 4 pulses. Transfer the dough to the greased tart pan and, working outward from the center, pat the dough into an even layer, sealing any cracks. Working around the edge, press the dough firmly into the corners of the pan and up the sides, using your thumb to level off the top edge. Lay plastic wrap over the dough and smooth out any bumps or shallow areas. Place the tart shell on a plate and freeze for 30 minutes.
2. Adjust an oven rack to the middle position and heat the oven to 375 degrees. Place the frozen tart shell (still in the tart pan) on a rimmed baking sheet. Gently press a piece of extra-wide heavy-duty foil that has been sprayed with vegetable oil spray against the dough and over the edges of the tart pan. Fill the shell with pie weights and bake until the top edge of the dough just starts to color and the surface of dough under the foil no longer looks wet, about 30 minutes. Remove the tart shell from the oven and carefully remove the weights and foil. Return the baking sheet with the tart shell to the oven and continue to bake, uncovered, until golden brown, 5 to 10 minutes. Set the baking sheet with the tart shell on a wire rack to cool while making the filling. (Do not turn off the oven.)
3. FOR THE FILLING: While the crust is baking, cook the bacon in a 12-inch nonstick skillet over medium heat until browned and crisp, 8 to 10 minutes. Using a slotted spoon, transfer the bacon to a paper towel–lined plate; set aside. Pour off all but 2 tablespoons bacon fat from the skillet (or add vegetable oil if needed to make this amount).
4. Add the onions, salt, and thyme to the skillet. Cover and cook until the onions release their liquid and start to wilt, about 10 minutes. Reduce the heat to low and continue to cook, covered, until the onions are very soft, about 20 minutes, stirring once or twice (if after 15 minutes the onions look wet, remove the lid and continue to cook for another 5 minutes). Remove the pan from the heat and cool for 5 minutes.
5. Whisk the eggs, half-and-half, and pepper together in a large bowl. Remove the thyme from the onions; discard. Stir the onions into the egg mixture until just incorporated. Spread the onion mixture over the bottom of the baked crust and sprinkle the reserved bacon evenly on top.
6. Bake the tart on the baking sheet until the center of the tart feels firm to the touch, 20 to 25 minutes. Set the baking sheet with the tart on a wire rack and cool for at least 10 minutes. Remove the tart pan ring, gently slide a thin-bladed spatula between the pan bottom and crust to loosen, and slide the tart onto a serving plate. Cut into wedges and serve.