For the Crust

1. Place the flour and salt in the bowl of a food processor fitted with its steel blade. With the motor on, add the butter through the feed tube. Process for 10 to 15 seconds. The dough should have a coarse mealy texture.
2. With the machine running, drizzle ice water through the feed tube—but make sure no ice cubes go in. Start with ¼ cup, then test the dough. It should come together when pressed between your fingers. If it’s too dry, drizzle in a little more water. If the dough gets too wet, add a little more flour.
3. Divide dough into two equal pieces. Form each piece into a ball, then flatten each one with the palm of your hand. Wrap the disks with plastic wrap and refrigerate for at least 30 minutes before rolling out. The raw pastry dough can be frozen for up to a month. Thaw dough overnight in the refrigerator.

For the Filling

1. Preheat the oven to 350 degrees and prepare the pastry crust; On a lightly floured work surface, roll out one disk of your pastry dough. Lightly spray a 9-inch tart pan with nonstick cooking spray. Place the rolled-out dough into the prepared pan. Try not to stretch the dough. Place the lined tart pan in the freezer for 30 minutes. Freezing the unfilled shell will keep the pastry from shrinking during the baking process. If you’re freezing it for more than a few hours, loosely wrap the tart shell with plastic wrap.
2. Cut your heirloom tomatoes into ¼-inch slices. Place the tomato slices on a paper-towel-lined baking sheet pan, lay more paper towel on top and press gently. Let the tomatoes rest while you prepare the filling. The paper towels will absorb excess water.
3. In a small sauté pan, heat the olive oil over medium heat. Add the shallots and garlic. Sauté for 1 minute until just translucent. Remove from heat.
4. In a mixing bowl, combine the eggs, half and half, oregano, salt, and white pepper. Stir in 3 tablespoons of the chopped fresh basil.
5. Place the prepared tart pan on a baking sheet. Spread the shallot garlic mixture across the bottom of the tart shell. Arrange half of the heirloom tomatoes on top of the shallots, interspersing smaller and larger ones.
6. Sprinkle half of the cheese evenly over the tomatoes. Gently pour the egg mixture into the tart pan. Sprinkle the remaining cheese on top of the egg mixture. Arrange the remaining heirloom tomatoes on top.
7. Bake in the preheated oven until the tart is set (about 40 minutes).
8. Remove the tart from the oven and let it rest for 5 minutes. Carefully lift the quiche out of the pan. Sprinkle the remaining fresh basil on top of the baked quiche. Slice and enjoy!