01 - Preheat the oven to 375°F.
02 - In a bowl, mix flour and salt. Cut in cold butter until the mixture resembles coarse crumbs. Add ice water, one tablespoon at a time, mixing until the dough just comes together. Form into a disk, wrap in plastic, and chill for 15 minutes.
03 - Roll out the dough on a lightly floured surface to fit a 9-inch pie dish. Gently press into the dish, trim excess, and prick the base with a fork. Chill for 10 minutes.
04 - Line the crust with parchment and fill with pie weights or beans. Bake for 15 minutes. Remove weights and parchment; bake 7–8 minutes more until lightly golden. Let cool slightly.
05 - Heat olive oil in a skillet over medium heat. Sauté leek for 2 minutes. Add asparagus and sugar snap peas; cook for 3–4 minutes until just tender. Stir in spinach and cook until wilted. Remove from heat.
06 - In a large bowl, whisk eggs, milk, cream, salt, pepper, and nutmeg. Stir in Gruyère and Parmesan cheeses.
07 - Spread sautéed vegetables and cherry tomatoes evenly in the crust. Pour egg mixture over the vegetables.
08 - Bake for 35–40 minutes, until the filling is set and lightly golden. Let cool 10 minutes before slicing.