Gruyère, Onion & Zucchini Quiche

Preheat oven to 375°F. Press pie crust into a 9-inch pie pan; fold overhanging dough edges under and pinch to crimp. Line the crust with parchment paper and fill with pie weights. Bake until golden brown and almost completely set, about 20 minutes. Remove from oven; remove pie weights and parchment paper. Let the crust cool completely, about 30 minutes. Reduce oven temperature to 350°F.

Meanwhile, heat 1 tablespoon oil in a large skillet over medium heat. Add onion; cook, stirring often, until deep golden and jammy, about 15 minutes, adding 2 tablespoons water every so often if the onions start to crisp or burn. Add sherry; cook, stirring constantly, until evaporated, about 1 minute. Remove from heat. Transfer the onions to a large bowl; set aside. Add the remaining 1 tablespoon oil to the pan and heat over medium-high heat. Add zucchini; cook, stirring occasionally, until starting to brown and soften, about 3 minutes. Transfer the zucchini to the bowl with the onion; let stand until completely cool, about 10 minutes.

Whisk eggs, half-and-half, salt, 1/2 cup cheese and 1 teaspoon thyme in a large bowl. Stir the cooled onion-zucchini mixture into the egg mixture. Pour the mixture into the cooled crust; sprinkle with the remaining 1/4 cup cheese. Loosely cover the crust edges with foil. Bake until puffed around the edges, set in the center and golden brown, 38 to 40 minutes. Sprinkle with the remaining 1 teaspoon thyme. Let stand for 15 minutes before serving.