Caramelized Onion, Mushroom and Spinach Quiche

Instructions

1. 1

   In a food processor, blend the flour and salt. Add the butter and pulse a few times, until it forms pea-sized pieces. Add the yogurt and water. Pulse just until the dough starts coming together. Add more water, as needed. Remove the dough from the food processor and form into a rectangle with your hands.

2. 2

   On a floured work surface, roll the dough into a 15 x 12-inch (38 x 30 cm) rectangle. Line a small 13 x 9-inch (33 x 23 cm) baking sheet with the dough. Refrigerate for 30 minutes.

3. 3

   With one rack in the middle of the oven and a second rack in the lowest position, preheat the oven to 400°F (200°C).

4. 4

   Prick the dough all over with a fork. Cover the dough with a sheet of foil and fill with pie weights or dry beans. Refrigerate.