3 medium yellow onions

4 tablespoons (1/2 stick) unsalted butter

1 1/2 teaspoons kosher salt, divided

1 teaspoon freshly ground black pepper, divided

1/4 cup finely chopped fresh chives

4 ounces Gruyere cheese, finely grated (about 1 cup)

1 1/2 cups half-and-half

6 large eggs

2 packed cups baby arugula

Extra-virgin olive oil, for drizzling

1. Arrange a rack in the middle of the oven and heat the oven to 375 F. Gently roll the pie crust out to about 12 inches in diameter and transfer it into a cast iron 10-inch skillet. Press the pie dough into the bottom and up the sides of the skillet. Roll or trim the edges so the dough is flush with the top of the pan and there’s no overhang. Poke the bottom and sides of the pie dough with a fork about 20 times. Bake until the edges are just beginning to brown, 15 to 18 minutes. Meanwhile, make the filling.

2. Thinly slice 3 medium yellow onions (about 5 cups). Melt 4 tablespoons unsalted butter in a large saucepan over medium heat. Add the onions, 1/2 teaspoon of the kosher salt, and 1/2 teaspoon of the black pepper, and cook, stirring often, until deep golden brown and very fragrant, 15 to 20 minutes. If the onions start to burn, add a tablespoon of water and continue cooking. Transfer the onions to a large bowl and let cool for 5 minutes. Meanwhile, finely chop until you have 1/4 cup fresh chives and finely grate 4 ounces Gruyere cheese (about 1 cup).

3. Add chives, Gruyere, 1 1/2 cups half-and-half, 6 large eggs, remaining 1 teaspoon kosher salt and remaining 1/2 teaspoon black pepper to the onions. Whisk until no streaks of yolk remains. Pour into the crust.

4. Bake until lightly browned and the eggs are fully set and do not jiggle, 28 to 30 minutes. Let cool for 10 minutes. Top with 2 packed cups baby arugula and drizzle with olive oil before slicing and serving.

Recipe notes: Leftovers can be covered and refrigerated up to four days. Serve cold or reheat in a 300 F oven until warmed in the center, about 15 minutes.

(Jesse Szewczyk is studio food editor for TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)

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