Leek and Celery Pie

Ingredients

• 1 tablespoon red-wine vinegar
• ¾ cup extra-virgin olive oil
• ½ cup whole-milk yogurt (preferably Greek)
• ¾ cup water
• 2 teaspoons salt
• 4 cups all-purpose flour
• 3 large eggs
• + 11 more ingredients
• • 5 large celery ribs
  • 6 pounds leeks
  • 1 teaspoon salt
  • 1 cup fresh mint
  • ²/₃ cup fresh flat-leaf parsley
  • ½ cup fresh dill
  • ¼ teaspoon black pepper
  • ¼ pound Greek feta (preferably Mt. Vikos or Dodoni brand), crumbled
  • 1 17- by 12-inch shallow heavy baking pan (1 inch deep)
  • 7 tablespoons extra-virgin olive oil
  • 1 ½ ounces finely grated Kefalotyri or Parmigiano-Reggiano cheese

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...

View full recipe at Epicurious