1cupleekswhite and light green parts only (about 1 small leek)
3cups fresh baby spinach
2large egg whites
1/4cupplain non-fat Greek yogurt
1/4 teaspoon kosher salt
1 cup crumbled reduced fat feta cheese(4 ounces)
For the Phyllo Dough Crust:
10 phyllo sheetsthawed, cut to be 12 inches on one side (the other side may be shorter depending upon the brand you purchase)
Preheat the oven to 350 degrees F. Heat the olive oil in a large skillet over medium high heat. Add the leeks and sauté 5 minutes, until tender. Add the spinach and sauté 2 minutes. Remove from heat and set aside.
In a large bowl, whisk together the eggs, egg whites, milk, Greek yogurt, salt, and pepper. Set aside.
Melt the butter in a small saucepan or microwave safe bowl. Brush a 9-inch pie plate or straight-sided skillet with melted butter. Unroll the phyllo sheets in a stack, trim as needed, the cover the stack with a damp kitchen towel. Place 1 sheet of phyllo in the pie plate and brush with more butter. Continue layering the phyllo sheets in so that they form overlapping circles, brushing each layer with more butter as you go. Keep the pile covered as you work with each sheet so that the phyllo does not dry out and become brittle. Transfer the pie plate to a rimmed baking sheet.
Spoon the spinach and leek mixture into the bottom of the crust, then sprinkle the feta over the top. Gently pour in the egg mixture. Bake the quiche on the pan for 45 to 55 minutes, until eggs are set in center and puffed slightly and the phyllo is golden brown. Let the quiche cool on a wire rack for 10 minutes. Slice and serve warm or at room temperature.