Mushroom and Leek Galette

The Mushroom and Leek Galette is a mouthwatering free-form vegetable tart that features a sturdy and flavorful crust. Unlike traditional fruit tarts, vegetable tarts can be challenging to work with due to their tendency to leak liquid into the crust or fall apart when sliced. This recipe addresses these issues by creating an extra-sturdy crust with a complex flavor, achieved by adding whole-wheat flour for an earthy taste and hearty texture. To ensure a tender dough, a gentle mixing approach is used, followed by a resting period before rolling it out. The dough is then folded multiple times to create a flaky texture with interlocking layers, enhancing its structure and flavor. The filling is a delightful combination of meaty shiitake mushrooms and sweet leeks, enriched with crème fraîche, Dijon mustard, and Gorgonzola cheese. The result is a savory and rich galette that perfectly showcases the flavors of the vegetables and the exceptional crust.

MAKES TWO 12-INCH GALETTES, SERVES 4 TO 6

INGREDIENTS:

DOUGH

• 1¼ cups (6¼ ounces) all-purpose flour
• ½ cup (2¾ ounces) whole-wheat flour
• 1 tablespoon sugar
• ¾ teaspoon salt
• 10 tablespoons unsalted butter, cut into ½-inch pieces and chilled
• 7 tablespoons ice water
• 1 teaspoon distilled white vinegar

FILLING

• 1¼ pounds shiitake mushrooms, stemmed and sliced thin
• 5 teaspoons extra-virgin olive oil
• 1 pound leeks, white and light green parts only, sliced ½ inch thick and washed thoroughly (3 cups)
• 1 teaspoon minced fresh thyme
• 2 tablespoons crème fraîche
• 1 tablespoon Dijon mustard
• Salt and pepper
• 3 ounces Gorgonzola cheese, crumbled (¾ cup)
• 1 large egg, lightly beaten
• Kosher salt
• 2 tablespoons minced fresh parsley

INSTRUCTIONS:

DOUGH

1. In a food processor, pulse together all-purpose flour, whole-wheat flour, sugar, and salt until combined. Add chilled butter pieces and pulse until pea-size pieces form, approximately 10 pulses. Transfer the mixture to a medium bowl.
2. Sprinkle ice water and distilled white vinegar over the mixture. Use a rubber spatula to gently fold the ingredients together until a loose, shaggy mass forms with some dry flour remaining. Be careful not to overwork the dough. Transfer the mixture to the center of a large sheet of plastic wrap, press it gently into a rough 4-inch square, and wrap it tightly. Refrigerate the dough for at least 45 minutes.
3. On a lightly floured counter, roll out the chilled dough into an 11 by 8-inch rectangle, with the short side of the rectangle parallel to the edge of the counter. Use a bench scraper to bring the bottom third of the dough up over the middle third, then fold the upper third over it, folding it like a business letter into an 8 by 4-inch rectangle. Turn the dough 90 degrees counterclockwise.
4. Roll out the dough again into an 11 by 8-inch rectangle and fold it into thirds once more. Turn the dough 90 degrees counterclockwise and repeat the rolling and folding into thirds. After the last fold, fold the dough in half to create a 4-inch square and press the top gently to seal. Wrap the dough in plastic wrap and refrigerate it for at least 45 minutes or up to 2 days.

FILLING

1. Microwave the sliced shiitake mushrooms in a covered bowl until just tender, for about 3 to 5 minutes. Transfer them to a colander to drain, then return them to the bowl.
2. In a 12-inch skillet, heat 1 tablespoon of olive oil over medium heat until shimmering. Add the sliced leeks and minced thyme. Cover and cook, stirring occasionally, until the leeks are tender and beginning to brown, for about 5 to 7 minutes. Transfer them to the bowl with the mushrooms. Stir in crème fraîche and Dijon mustard, and season the mixture with salt and pepper to taste. Set aside.

ASSEMBLY AND BAKING

1. Adjust the oven rack to the lower-middle position, place a baking stone on the rack, and preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius).
2. Remove the dough from the refrigerator and let it stand at room temperature for 15 to 20 minutes. Roll it out on a generously floured counter to a 14-inch circle, about ⅛ inch thick. Trim the edges as needed to form a rough circle, then transfer the dough to a parchment paper–lined rimmed baking sheet.
3. Using the tip of a paring knife, cut five ¼-inch circles in the dough (one at the center and four evenly spaced midway from the center to the edge of the dough). Brush the top of the dough with 1 teaspoon of olive oil.
4. Spread half of the filling evenly over the dough, leaving a 2-inch border around the edge. Sprinkle half of the crumbled Gorgonzola cheese over the filling, then cover it with the remaining filling and top with the remaining Gorgonzola. Drizzle the remaining 1 teaspoon of olive oil over the filling.
5. Fold the outer 2 inches of dough up and over the filling, working your way around the circumference of the tart, overlapping the dough every 2 to 3 inches. Gently pinch the pleated dough to secure it, but avoid pressing it into the filling. Brush the exposed dough with beaten egg and sprinkle it evenly with kosher salt.
6. Lower the oven temperature to 375 degrees Fahrenheit (190 degrees Celsius). Bake the galette until the crust is deep golden brown and the filling is beginning to brown, which should take about 35 to 45 minutes, rotating the sheet halfway through baking.
7. Allow the galette to cool on the baking sheet on a wire rack for 10 minutes. Using an offset or wide metal spatula, loosen the galette from the parchment and carefully slide it off the parchment onto a cutting board. Sprinkle the galette with minced fresh parsley, cut it into wedges, and serve.

VARIATIONS:

Potato and Shallot Galette with Goat Cheese

• Substitute the mushroom filling in step 4 with the following: Microwave 1 pound of Yukon Gold potatoes, sliced ¼ inch thick, in a covered bowl until just tender, for about 4 to 8 minutes. Drain them and return them to the bowl. Heat 1 tablespoon of oil in a 12-inch skillet over medium heat until shimmering. Add 4 ounces of thinly sliced shallots and 1 teaspoon of minced fresh rosemary. Cover and cook until the shallots begin to brown, for about 5 to 7 minutes. Add them to the potatoes. Stir in ¼ cup of crème fraîche, ¼ cup of chopped Kalamata olives, and 1 teaspoon of grated lemon zest. Season the mixture with salt and pepper to taste. Substitute ¾ cup of crumbled goat cheese for Gorgonzola cheese.

Butternut Squash Galette with Gruyère

• Substitute the mushroom filling in step 4 with the following: Microwave 6 cups of baby spinach and ¼ cup of water in a covered bowl until wilted by half, for about 3 to 4 minutes. Let the spinach stand, covered, for 1 minute, then drain it thoroughly. Chop the spinach coarsely and drain it again while pressing with a rubber spatula to remove excess liquid, then return it to the bowl. Microwave 3 cups of butternut squash, cut into ½-inch cubes, in a covered bowl until just tender, for about 8 minutes. Drain the squash and add it to the spinach. Heat 1 tablespoon of oil in a 12-inch skillet over medium heat until shimmering. Add 1 thinly sliced red onion and ½ teaspoon of minced fresh oregano. Cover and cook until the onion begins to brown, for about 5 to 7 minutes. Add the onion to the spinach and squash. Stir in ¾ cup of shredded Gruyère cheese, 2 tablespoons of crème fraîche, and 1 teaspoon of sherry vinegar. Season the mixture with salt and pepper to taste. Omit the Gorgonzola cheese when assembling the tart.