Ingredients
Equipment
Method
- Make the crust: In a large bowl, whisk together flour and salt. Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs. Gradually add ice water, 1 tablespoon at a time, mixing until the dough just comes together.
- Form the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.
- Caramelize the onions: While the dough chills, heat olive oil and butter in a large skillet over medium-low heat. Add the sliced onions and cook slowly, stirring occasionally, for 25-30 minutes, or until deeply golden brown and sweet. Set aside.
- Preheat oven to 375°F (190°C). On a lightly floured surface, roll out the dough into a 12-inch circle. Carefully transfer the dough to a 9-inch tart pan with a removable bottom, pressing it into the bottom and up the sides. Trim any excess dough.
- Blind bake the crust: Line the tart shell with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes. Remove the parchment and weights, and bake for another 5 minutes, or until lightly golden.
- Prepare the filling: In a medium bowl, whisk together eggs, heavy cream, Parmesan cheese, thyme, salt, and pepper.
- Assemble the tart: Spread the caramelized onions evenly over the bottom of the pre-baked tart shell. Arrange the cubed butternut squash over the onions.
- Pour the egg mixture over the squash and onions, ensuring it fills the gaps.
- Bake: Bake for 25-30 minutes, or until the filling is set and the top is golden brown. Let the tart cool in the pan for 10 minutes before removing the outer ring.
- Serve warm.
Notes
You can add other vegetables like spinach or mushrooms to the filling. Ensure the butternut squash is cut into uniform pieces for even cooking.