1 ½ cups all-purpose flour, plus extra for rolling dough
¾ cup shredded sharp cheddar cheese, divided
8 tablespoons very cold unsalted butter, cut into chunks
⅛ teaspoon + ½ teaspoon kosher salt, divided
¼ cup very cold water
½ white onion
1 tablespoon olive oil
2 medium-large zucchini (about 1 pound total)
3 tablespoons grated Parmesan cheese, divided
½ cup milk, preferably 2%
3 eggs
1 teaspoon baking powder
1 teaspoon lemon zest
¼ teaspoon herbes de Provence
¼ teaspoon freshly ground black pepper
Directions
To make the pie dough, add the flour, 1/4 cup cheddar cheese, butter, and salt into a food processor and pulse until the butter is in no bigger than pea-sized chunks.
Add the water, and run the processor until the dough just begins to clump together.
Dump the dough out of processor onto a sheet of plastic wrap.
Shape the dough into a round disk and wrap it up in the plastic wrap.
Chill the dough in the refrigerator for at least 4 hours (24 hours is ideal).
After dough has been chilled, preheat the oven to 400 F
Sprinkle the extra flour onto a work surface and place the unwrapped dough on it.
Roll the dough into a 12-inch circle, about 1/8-inch thick.
Carefully place the dough into a 9.5-inch pie plate, trimming any excess dough hanging over the side. Use your fingers to crimp the edge of the crust.
Use a fork to prick the bottom of the crust several times, then line the dough with parchment paper and fill it with pie weights, covering the entire bottom surface of the dish.
Bake the crust for 20 minutes, until the edges are golden brown. Then remove the parchment paper and pie weights and bake it for another 5 minutes, until the bottom of the pie crust no longer looks raw. Remove it from the oven and set it aside.
To prepare the filling, start by peeling and finely chopping the onion.
Heat a small-medium nonstick skillet over medium-high heat and add the olive oil.
Add the onion and cook for 5 to 7 minutes, until lightly browned, then let cool.
Cut off both ends of the zucchinis and shred the flesh using a cheese grater or a food processor with shredder attachment.
Place the shredded zucchini into a bowl lined with a clean kitchen towel, then bring the edges of the towel up around zucchini, twist tightly, and squeeze out as much liquid as you can.
Pour the liquid out of the bowl and place the zucchini into the bowl without the towel.
Add the cooled onion, remaining cheddar cheese, 2 tablespoons of Parmesan cheese, milk, eggs, baking powder, lemon zest, remaining salt, herbes de Provence, and pepper, and stir until all ingredients are incorporated.
Pour the zucchini filling into the pie crust, then top it with the remaining tablespoon of Parmesan cheese.
Bake for 35 to 45 minutes, until pie is puffed and lightly browned, and the filling doesn't jiggle.