Winter Vegetable Crostata

PHOTOS BY MICHAEL PIAZZA / STYLED BY CATRINE KELTY

I made this savory tart last Thanksgiving for a vegetarian friend. At first, I was stumped by what to make that would be festive, hearty, and tasty enough for others to enjoy besides the one, meat-eschewing diner. After a quick internet search, I landed on "Kuri Squash, Mushroom and Kale Tart with Rosemary Crust," a recipe from Tara Parker Pope’s New York Times story "Vegetarian Thanksgiving: Vegetable Tarts, Big and Small." I had all the ingredients in the fridge (bonus!), and it looked gorgeous in the photo. But Pope’s recipe was almost vegan, and my friend is definitely not, so I added heavy cream, an egg, some more cheese, and used a leftover slab of butter-rich pâte brisée from my pie–making marathon the day before. I’m a huge fan of crust, so I baked the tart as a free-form crostata rather than in the suggested fluted tin, leaving a thick overlap of crisp, buttery crust on the edge—like a pizza, but better. That switch makes this a much easier tart to make, since there’s no “blind baking” or leftover pastry scraps.

Serves 6-8.

Ingredients:
3 onions, thinly sliced
1 bay leaf
1 large sprig fresh thyme
Extra virgin olive oil
Kosher or sea salt
Fresh ground black pepper
1 small winter squash (butternut or kabocha work well), about 1½ pounds, peeled, seeded and sliced into ¼” slices
2 cloves garlic, minced
8-10 fresh sage leaves, slivered
1 bunch black Tuscan kale, stems removed and leaves thinly sliced
Pinch dried red chili flakes, optional, if you like a bit of heat
6–8 ounces wild mushrooms, like Hen of the Woods or chanterelles, sliced or torn into bite-sized pieces
½ recipe Flaky Pâte Brisée for Savory Tarts, see page 27
1 tablespoon fresh thyme leaves
Pinch freshly grated nutmeg
6 ounces local, Alpine-style cheese, like Robinson Farm’s “A Barndance,” or any Swiss or French Alpine cheese (like Gruyère or Comté), grated
¾ cup heavy cream
1 egg, beaten

Directions:

Preheat the oven to 400°F.

In a heavy skillet, heat 2 tablespoons olive oil and add the onions, bay leaf, and thyme sprig. Season with salt and a pinch of sugar and allow it to caramelize, stirring occasionally, until deeply browned, at least 20–30 minutes. Remove the bay leaf and thyme sprig.

While the onions caramelize, toss the sliced squash in a bowl with some olive oil to coat, ¼ teaspoon salt, some black pepper, half the garlic, and the sage. Arrange on two parchment-lined baking sheets and roast in the hot oven for 15 minutes or until the edges have begun to brown and the squash is soft all the way through. Set aside.

Heat 2 tablespoons oil in another skillet and add the kale leaves and remaining garlic, seasoning with salt and the optional chili flakes and tossing until wilted and softened, about 8-10 minutes. Add a tablespoon of water to help it along, if needed. Remove the kale from the pan and add another 2 tablespoons of oil, heat it until it shimmers, then add the mushrooms and a good pinch of salt. Cook, tossing them in the oil, until they give up their liquid and begin to crisp a bit. Remove from the heat and set aside.

On a large sheet of parchment paper, roll out the pie dough to about a 14-inch round. Transfer the round and parchment to a baking sheet and chill 5 minutes in the freezer.

To assemble the crostata, spread the cooled caramelized onions in the middle of the dough, leaving at least 2 inches at the edge. Top with an even layer of the sliced squash and sprinkle with some of the thyme leaves, the nutmeg, and ¼ of the grated cheese. Arrange the mushrooms on top and sprinkle with more thyme leaves and another ¼ of the cheese, followed by the kale, more thyme, and cheese.

Fold the outer 2 inches of dough in over the filling; flute the folds if you like. Whisk together the heavy cream and the egg and pour over the filling, being careful not to let it spill out; if you dribble it in, a little at a time, it will have time to settle between additions so you can add more. Sprinkle with the remaining cheese and a bit more salt and pepper.

Bake in a 400°F oven for 30–35 minutes or until center is bubbly and the pastry is golden brown. Let stand for 5–10 minutes before cutting into slices; can be made ahead and served warm (reheated) or at room temperature.

Sarah Blackburn is a home cook, recipe developer, vegetable gardener and managing editor of Edible Boston. She can be reached at sarah@edibleboston.com