Description
A savory and elegant Cauliflower and Caramelized Onion Tart featuring tender roasted cauliflower, sweet caramelized onions, creamy mascarpone filling, and a blend of Gruyère and Parmesan cheeses in a flaky pie crust. Perfect as a sophisticated appetizer or a light main course.
Ingredients
Scale
Vegetables
- 1 small head of cauliflower (about 1 pound), cored, cut into 1-inch florets
- 1 large onion, halved lengthwise, thinly sliced
Oils & Fats
- 1/2 tablespoons olive oil, divided (1 tablespoon + 1 1/2 tablespoons)
- 1 tablespoon truffle oil
Dairy & Eggs
- 1 refrigerated pie crust
- 2 large eggs
- 1 (7- to 8-ounce) container mascarpone cheese (Italian cream cheese)
- 1/2 cup whipping cream
- 1 cup grated Gruyère cheese
- 3/4 cup grated Parmesan cheese
Condiments & Spices
- 1 tablespoon Dijon mustard
- 1/4 teaspoon ground white pepper
- Pinch of ground nutmeg
- Salt and pepper to taste
Instructions
- Roast Cauliflower: Preheat the oven to 425°F (220°C) and position the rack in the center. Toss the cauliflower florets with 1 tablespoon olive oil, salt, and pepper. Spread them evenly on a rimmed baking sheet and roast for 15 minutes. Turn the florets over and continue roasting for about 25 more minutes until tender. Remove from oven, cool slightly, then thinly slice. Drizzle with truffle oil and toss gently to coat. Reduce oven temperature to 350°F (175°C) for later use.
- Prepare Pie Crust: Press the refrigerated pie crust into a 9-inch tart pan with a removable bottom, covering the bottom and sides. Line the crust with foil and fill with pie weights to prevent bubbling. Bake for 20 minutes, then remove the foil and weights and bake for an additional 5 minutes until the crust turns golden. If bubbles form, gently press them down with the back of a fork. Let the crust cool completely while maintaining the oven temperature.
- Caramelize Onions: Heat the remaining 1 1/2 tablespoons olive oil in a heavy large skillet over medium heat. Add the sliced onions and sprinkle with salt and pepper. Cook, stirring occasionally, for about 40 minutes until the onions become deep golden brown and caramelized. Remove from heat and let cool slightly. (Note: Onion and crust can be prepared a day ahead; store crust at room temperature and refrigerate onions and cauliflower separately.)
- Assemble the Tart: Brush the inside of the cooled crust (bottom and sides) with Dijon mustard. Spread the caramelized onions evenly across the crust. Arrange the sliced roasted cauliflower over the onions in an even layer. Place the tart pan on a rimmed baking sheet for easy handling.
- Prepare Filling and Bake: In a medium bowl, whisk together eggs, mascarpone cheese, whipping cream, ground white pepper, and nutmeg until smooth. Stir in the grated Gruyère cheese. Pour this mixture over the vegetables in the tart crust. Sprinkle grated Parmesan cheese evenly on top. Bake at 350°F for about 40 minutes, or until the tart is golden and the center is set. Remove from oven and transfer to a wire rack to cool for 15 minutes before serving.
Notes
- The tart can be prepared a day in advance—caramelize onions and roast cauliflower ahead, store separately in the refrigerator, and keep the baked crust at room temperature.
- Using truffle oil adds a luxurious, earthy aroma to the roasted cauliflower.
- Ensure onions are cooked slowly to achieve deep caramelization without burning.
- Gruyère cheese provides a creamy, nutty flavor, while Parmesan adds a sharp finish on top.
- The tart is delicious served warm or at room temperature, perfect for entertaining or a cozy meal.
- Prep Time: 25 minutes
- Cook Time: 1 hour 20 minutes
- Category: Tart
- Method: Baking
- Cuisine: French
Keywords: cauliflower tart, caramelized onion tart, vegetarian tart, savory tart, roasted cauliflower, mascarpone tart, Gruyère cheese tart
