Makes one 9-inch tart
Parmesan Pastry Dough
- 1 cup all-purpose flour
- 1/4 teaspoon kosher salt
- 6 tablespoons unsalted butter, cold, cut into 3/4-inch cubes
- 1/4 cup finely grated Parmesan cheese
- 1 to 2 tablespoons ice cold water, plus more as needed
- 1 small cauliflower (about 12 oz), cut into bite-size florets
- 3 tablespoons olive oil
- 3/4 teaspoon kosher salt
- 1/4 teaspoon freshly ground black pepper
- 1 cup sour cream
- 1/4 cup heavy cream
- 2 large eggs
- 1/2 teaspoon mustard powder
- 3/4 cup coarsely grated Gruyère, packed
- 1/4 cup grated Parmesan, packed
- In a large bowl, combine the flour and salt. Scatter the butter pieces over the dry ingredients.
- Using a pastry blender or by rubbing the mixture between your fingers, quickly cut or rub the butter into the dry ingredients until it is in pieces no bigger than small walnuts but no smaller than peas. Add the cheese and toss gently to combine.
- Sprinkle half of the ice-cold water over the butter mixture. Using your hands or a rubber spatula, lightly toss the dry mixture to incorporate the water. Do not overwork the dough, or the butter may melt. Continue to add water in small amounts until the dough is rough but pliable and just holds together when pressed to the side of the bowl. The mixture should not form a ball or mass of dough in the bowl.
- Turn out the dough onto a lightly floured work surface. Shape it into a 5- to 6-inch disc and wrap it tightly in plastic wrap. Refrigerate for at least 1 hour, or preferably overnight, until firm.
- Preheat the oven to 400°F.
- In a medium bowl, toss the cauliflower with the oil, 1/4 teaspoon of the salt, and the pepper. Spread the cauliflower in an even layer on a rimmed baking sheet and roast until soft and golden brown, 20 to 30 minutes. Remove the pan from the oven and place it on a cooling rack.
- Line the chilled crust with lightly oiled or sprayed parchment and fill with weights. Partially blind bake the crust until it is a matte, pale golden color, 15 to 20 minutes. Transfer the crust to a cooling rack and remove the weights and parchment. Reduce the oven temperature to 350°F.
- In medium bowl, combine the sour cream, heavy cream, eggs, the remaining 1/2 teaspoon salt, and the mustard powder and whisk until thick and smooth.
- Sprinkle half of the Gruyère and Parmesan over the bottom of the prepared crust and arrange the cauliflower in an even layer over the cheeses. Pour the sour cream mixture over the cauliflower and sprinkle with the remaining cheeses.
- Bake until the center of the tart is just set and the edges are golden brown, 20 to 25 minutes. If more top color is preferred, switch the oven to a broil setting and broil for 3 to 4 minutes, or until the cheeses begin to brown.
- Remove the tart from the oven and place it on a cooling rack.
- Serve warm or at room temperature.