Mushroom, Leek and Gruyere Tart
If vegetables were looking to elect a spokesperson, I’d nominate mushrooms. A bit of heat brings out the best in them. And when things get downright hot, they maintain their composure, refusing to dissolve into an incoherent mash. They work graciously with almost any herb, are effusively complementary to dairy, and are as comfortable with fancy-dress pastry as they are with a Casual Friday slice of toast. With a support staff of herbs, cheese, and garlic, this recipe lets the earthiness of mushrooms shine.
Recipe courtesy of Charmian from The Messy Baker.
Prep Time: 30 mins. | Cook Time: 20 mins. | Serves: 4-6
NOTE: This tart is best eaten as soon as it is cool enough to handle. Leftovers can be wrapped and refrigerated, but the pastry will suffer. To reheat, pop under the broiler for a few minutes. Do not reheat in the microwave.
1 sheet commercial puff pastry or homemade Cheater’s Puff Pastry (page 44), defrosted
3 tablespoons unsalted butter
2 cloves garlic
2 sprigs fresh thyme, leaves only (see tip)
2 cups thinly sliced leeks, white parts only, sliced lengthwise and slivered into half moons
16 ounces cremini or Portobello mushrooms, cut into 1″ pieces
Ground black pepper (optional)
3 ounces grated Gruyère cheese
To strip the thyme leaves from the stem in seconds, simply grasp the top of the sprig between your thumb and index finger. Using your other hand, gently pull the stem through your pinched fingers. The leaves will strip right off, no chopping required. This also works for rosemary, although you might want to mince the rosemary leaves, depending on the use.
1. Preheat the oven to 425°F.
2. On a sheet of parchment paper cut to fit a rimmed baking sheet, roll the puff pastry sheet out to a 10″ square. Using a sharp knife, gently score the pastry an inch inside the outer edge, being careful not to cut all the way through. Place the parchment with the scored pastry onto a rimmed baking sheet. Refrigerate while you prepare the filling.
3. In a large skillet over medium heat, melt the butter. When it bubbles, grate the garlic on a microplane into the pan. Add the thyme. Cook gently for 1 minute. Add the leeks and cook until they begin to soften. Add the mushrooms and cook until they are soft but not weeping juices. Place the mushroom filling into a strainer and let drain for a few minutes.
4. Spoon the mushroom filling onto the pastry, being careful to keep inside the score marks. Add a grinding of fresh black pepper, if using. Bake for 15 minutes. Remove the tart from the oven and sprinkle with the cheese. Bake for 5 minutes, or until the cheese has melted and the pastry is golden brown. Serve while hot.