Mushroom and Leek Galette

Ingredients

 * ¼ cup chopped fresh flat-leaf parsley
 * 1 large egg white for glaze
 * 1 tbsp olive oil
 * 4 medium leeks (white and light green parts only), sliced (2 cups)
 * 12 oz cremini or baby bella mushrooms, sliced (6 cups)
 * 1 large egg
 * ⅓ cup reduced-fat sour cream
 * ¾ tsp salt
 * ¼ tsp freshly ground pepper
 * 1 bunch scallions (white and light green parts only), sliced (⅓ cup)

Crust

 * 1½ cups all-purpose flour
 * 1½ tsp baking powder
 * ½ tsp salt
 * ½ cup low-fat cottage cheese
 * ¼ cup vegetable oil
 * ¼ cup low-fat milk
 * 1½ tsp sugar

Crust

 * 1) In medium bowl, whisk together flour, baking powder and salt.
 * 2) In food processor, process cottage cheese until puréed.
 * 3) Add oil, milk and sugar and process until smooth.
 * 4) Add flour mixture and pulse 4 to 5 times, just until dough clumps together.
 * 5) Turn dough out onto lightly floured surface and knead several times; do not overwork.
 * 6) Press dough into a disk, dust lightly with flour and wrap in plastic wrap.
 * 7) Refrigerate at least 20 minutes.

Gallette

 * 1) Meanwhile, in large nonstick skillet, heat oil over medium heat.
 * 2) Add leeks and cook, stirring often, until tender, 4 to 5 minutes, adding a little water if necessary to prevent scorching.
 * 3) Add mushrooms, increase heat to medium-high and cook, stirring, until mushrooms are tender, 3 to 4 minutes.
 * 4) Remove from heat and cool completely.
 * 5) Preheat oven to 400 °F.
 * 6) Coat baking sheet with cooking spray.
 * 7) In large bowl, whisk together whole egg, sour cream, salt and pepper.
 * 8) Add scallions, parsley and cooled leek mixture; mix well.
 * 9) On lightly floured surface, roll out dough into 15-inch circle about ¼ inch thick.
 * 10) Roll dough back over rolling pin and transfer to prepared baking sheet.
 * 11) Spread leek mixture over dough, leaving 2-inch border around edges.
 * 12) Fold dough border up and over filling, pleating as necessary.
 * 13) In small bowl, combine egg white with 1 tablespoon water; stir briskly with fork.
 * 14) Brush over rim of crust.
 * 15) Bake until crust is golden, 30 to 35 minutes.
 * 16) Transfer baking sheet to wire rack and let cool 5 minutes.
 * 17) Carefully slide galette onto platter and serve hot or at room temperature.