Leek and Celery Pie

Ingredients

• •4 cups all-purpose flour plus additional for dusting
• •2 teaspoons salt
• •¾ cup water
• •½ cup whole-milk yogurt (preferably Greek)
• •¾ cup extra-virgin olive oil
• •1 tablespoon red-wine vinegar
• •6 lb leeks (white and pale green parts only), finely chopped (about 10 cups)
• •¼ cup plus 3 tablespoons extra-virgin olive oil
• •5 ribs large celery ribs, finely chopped (about 3 cups)
• •1 teaspoon salt
• •1 cup chopped fresh mint
• •⅔ cup chopped fresh flat-leaf parsley
• •½ cup chopped fresh dill
• •¼ lb Greek feta (preferably Mt. Vikos or Dodoni brand), crumbled (1 cup)
• •1½ oz Kefalotyri or Parmigiano-Reggiano cheese
• •¼ teaspoon black pepper
• •3 large eggs
• •1 pan 17- by 12-inch shallow heavy baking pan

Cooking Instructions

1. 1.

   Stir together flour and salt in a large bowl, then make a well in center and add water, yogurt, 1/2 cup oil, and vinegar. Stir until a soft dough forms, then knead on a work surface (do not dust with flour) until smooth and pliable, about 4 minutes. Form dough into a ball and put in an oiled bowl, then turn to coat. Cover bowl with plastic wrap and let dough stand at room temperature 1 hour.

   60 min

2. 2.

   Wash leeks in a bowl of cold water, agitating them, then lift out and drain well in a colander.

   5 min

3. 3.

   Heat 1/4 cup oil in a deep 12-inch heavy skillet or a 5- to 6-quart heavy pot over moderately high heat until hot but not smoking, then sauté leeks and celery with 1/2 teaspoon salt, stirring frequently, until softened and translucent, 10 to 12 minutes. Transfer to a bowl and cool, stirring occasionally, 10 minutes.

   22 min

4. 4.

   Put oven rack in middle position and preheat oven to 375°F.

   10 min

5. 5.

   Stir herbs into leek mixture along with cheeses, pepper, and remaining 1/2 teaspoon salt. Lightly beat eggs with remaining 3 tablespoons oil in a small bowl, then stir into leek filling.

   5 min

6. 6.

   Brush baking pan with 2 tablespoons oil.

   2 min

7. 7.

   Divide dough in half. Roll out 1 half on a floured surface with a floured rolling pin into a 19- by 14-inch rectangle. Fold rectangle loosely into quarters and transfer to baking pan, then unfold dough and fit into pan, leaving a 1-inch overhang. Spread filling evenly in pan.

   10 min

8. 8.

   Roll out remaining dough on floured surface with floured rolling pin into a 20- by 15-inch rectangle. Lift dough and drape it over filling, leaving it slightly wrinkled. Roll edge of bottom crust over top to form a rope edge all around pie. Brush top of pie with remaining 2 tablespoons oil. Score top crust into serving pieces with a sharp knife (mark crust but do not cut through it).

   15 min

9. 9.

   Bake pie until golden brown, 50 to 60 minutes. Cool to room temperature in pan on a rack, about 1 hour.

   120 min