01 - Preheat oven to 375°F.
02 - Combine flour and salt in a bowl. Cut in cold butter until mixture resembles coarse crumbs. Add ice water one tablespoon at a time, mixing until dough holds together. Shape into a disk, wrap, and refrigerate for 20 minutes.
03 - Roll dough on floured surface to fit a 9-inch tart pan. Press dough into pan and trim excess. Prick base with fork. Line with parchment and fill with pie weights or dry beans.
04 - Bake crust for 15 minutes. Remove weights and parchment, then bake 5 additional minutes. Set aside to cool.
05 - Heat olive oil in skillet over medium heat. Cook asparagus and zucchini for 3-4 minutes until just tender. Add spinach, scallions, and peas; cook 1-2 minutes longer. Remove from heat and cool slightly.
06 - Whisk eggs, heavy cream, whole milk, salt, pepper, and nutmeg until fully combined. Stir in half the grated cheese.
07 - Spread sautéed vegetables evenly over prebaked crust. Pour custard mixture over vegetables. Sprinkle remaining cheese on top.
08 - Bake for 30-35 minutes until filling is set and top is golden brown.
09 - Cool quiche for 10 minutes before slicing and serving warm or at room temperature.