To make the pie dough:

1. Stir the flour, sugar and salt together. Use a pastry cutter or the backs of two forks to cut in the butter until there are pea-sized clumps throughout. Add about 6 tablespoons of the ice water into the flour mixture and begin to stir together. It will likely be dry and require more ice water, so keep adding water 2 tablespoons at a time until a shaggy dough comes together. Dump the mixture out on the counter and use your hands to form the dough into one ball. It should come together as a dough without feeling wet or too tacky. Cut the ball in half and flatten each half into a disk. Wrap each with plastic wrap and store in the fridge for at least an hour or up to a week. You will only need one half of the dough for this quiche. The other can be wrapped in foil and frozen for up to two months.
2. To prep the quiche:
3. Preheat the oven to 375 degrees. Use a floured rolling pin to roll the dough out onto a floured work surface into a round of dough about an inch and a half wider on all sides than your 9” tart dish. Roll the dough back onto the rolling pin and the transfer it to the dish, unrolling as you go. Gently work the dough into the edges of the dish and trim off any excess dough, leaving about an inch of excess hanging on all sides.  Fold the dough under itself and gently crimp the edges into the dish, allowing the top of the dough to extend about ¾-1” above the lip of the dish. This will help keep your crust tall even after baking. If your dough has gotten soft or warm while rolling it out, place it in the freezer for 5-10 minutes to chill up again.
4. When ready to bake, place a crinkled sheet of parchment paper into the bottom of the crust and fill it with pie weights or uncooked dry beans. Bake in the preheated oven about 10 minutes, then remove the paper and weights and bake for an additional 5-10 minutes, or until the bottom of the crust doesn’t look too wet and soggy. While the crust is baking, begin to assemble your filling.
5. Whisk together the milk, 4 eggs, garlic powder, salt and pepper. When the crust is finished baking, crack your additional egg in a separate bowl and brush a thin layer of egg white over the bottom of the crust. This will help to keep the crust from becoming soggy. Sprinkle the parmesan evenly over the crust and then spread out the roasted veggies. Sprinkle on the cheddar cheese and then carefully pour the egg mixture into the dish. Be careful to not overflow the tart or the eggs could run over the edge of the crust and into the bottom of your dish. Whisk together the egg from the egg wash and use a pastry brush to brush a thin layer over the exposed crust. Bake in the preheated oven for about 35 minutes or until the top is golden and the center is no longer jiggly. Serve warm or reheat individual slices in the toaster oven!