I don’t know anyone who wouldn’t like to eat caramelized onions. Although not everyone likes the smell of them cooking. This tart is so good that even the most dedicated haters of cooking onion aroma will change their mind after having a bite.
The recipe is adapted from Susan Spungen’s “Recipes: A Collection for the Modern Cook”
Makes one 9- inch round or long rectangular 3×14 tart, 6 to 8 servings
For the crust:
The ingredients listed below make two 9-inch pie or tart shells, or enough for a double-crust pie. You will need only half of the dough for this recipe. Scale the recipe down if you want but it’s worth to make a double batch. You can freeze another half, tightly wrapped, for later use. It can be kept in a freezer for up to a month. I like to roll this extra dough and fit it into the tart or pie pan, and freeze the dough already in a pan. It’s not even necessary to defrost the shell before prebaking.
- 2 ½ cups all-purpose flour
- 1 ½ sticks (12 tbsp) cold unsalted butter, cut into ½-inch cubes and frozen for 15 minutes
- ¼ cup cold vegetable shortening, preferably trans-fat-free, frozen for 15 minutes
- ½ tsp salt
- 8 tbsp ice water
For the filling:
- 4 slices bacon, cut into ½-inch pieces
- 4 small onions, cut in half lengthwise and thickly sliced
- 1 tbsp plus 1 tsp thyme leaves, chopped
- Kosher salt
- 1 cup ricotta
- 1 large egg yolk
- Pinch of freshly ground black pepper
- ¼ cup plus 1 tbsp freshly grated Parmigiano-Reggiano
Make the crust:
Pulse in a food processor the flour, butter, shortening, and salt just until the mixture resembles a coarse meal with some small (pea-size) butter lumps.
Drizzle 5 tbsp ice water evenly over the mixture. Pulse until incorporated. Squeeze a small handful of the dough: if it doesn’t hold together, add more ice water, ½ tbsp at a time, pulsing until combined. Do not overwork the dough, or the crust will be tough.
Turn the dough out onto a work surface. Divide the dough into 8 portions. With a heel of your hand, smear each portion once or twice in a forward motion to help distribute the fat. Gather the all dough together then divide it in half. Flatten each half into a disk. Wrap each disk in plastic wrap and chill until firm, at least 1 hour. The dough can be chilled up to 2 days.
Reserve one half of the dough for another use (if you made the double batch).
Roll out another portion of the dough to ¼-inch thickness, fit it into a 9-inch tart pan, lightly buttered. Freeze for about 30 minutes. Meanwhile preheat the oven to 400 F. Line the shell with buttered aluminum foil, a shine side down. Fill the foil with pie weights or dry beans. Bake for 25 minutes. Carefully remove the foil and the pie weights. Return the crust to the oven for additional 10 minutes, until light golden. Cool the crust on a rack while preparing the filling.
Make the filling, bake the tart:
Reduce the oven temperature to 350 F. Cook the bacon in a medium frying pan over medium-high heat until the fat is mostly rendered and the bacon is crisp around the edges. Don’t cook it too much now as it will be cooking again on top of the tart. Transfer to paper towels to drain and set aside, leaving 1 tbsp of the bacon fat in the pan.
Add the onions to the pan and cook over medium-high heat until they start to brown, about 8 minutes. Turn the heat to medium-low and add 1 tbsp of the thyme and a pinch of salt. Continue to cook until the onions are meltingly soft and deep golden brown, about 20 minutes more. Add more salt, according to your taste.
Meanwhile, combine the ricotta, egg yolk, ½ tsp salt, the pepper, the remaining 1 tsp thyme, and ¼ sup of the Parmigiano in a small bowl. Stir well to combine.
Spread the ricotta mixture evenly on the bottom of the tart shell. Arrange the onions on top of the ricotta and sprinkle with the remaining 1 tbsp Parmigiano. Sprinkle the bacon over the top. Transfer to the oven and bake for about 30-40 minutes, until the bacon is crispy and ricotta filling is puffed and set. Serve warm or at room temperature.
