Zucchini Ricotta Galette

          PASTRY:
 1¼    cups all-purpose flour, chilled in freezer for 30 minutes
   ¼    tsp. salt
    1    stick cold, unsalted butter, cut into pieces
   ¼    cup sour cream
    2    tsp. fresh lemon juice
   ¼    cup ice water

         FILLING:
   2    small zucchinis, sliced into ¼-inch rounds
   1    T. plus 1 tsp. olive oil
1-2    garlic cloves, minced
  ½    cup ricotta cheese
  ½    cup grated parmesan cheese
  ¼    cup shredded mozzarella cheese
         Salt and pepper
   1    T. basil leaves
         Egg

Whisk flour and salt in a large bowl. Using a pastry blender, cut in butter, until the mixture resembles a course meal, with the biggest pieces of butter the size of tiny peas. In a small bowl, whisk together sour cream, lemon juice and water, then add to flour mixture. Mix until large lumps form and pat into a ball; do not overwork the dough. Cover with plastic wrap and refrigerate 1 hour.

Spread the zucchini over several layers of paper towels, sprinkle with ½ tsp. salt and let sweat for 30 minutes. Blot excess water from zucchini before using. In a small bowl, combine olive oil and garlic. In a separate bowl, mix the cheeses and 1 tsp. of the garlicky olive oil, and season with salt and pepper, to taste.

On a floured work surface, roll out dough into a 12-inch round. Transfer to a parchment-lined baking sheet. Spread the ricotta mixture evenly over the dough, leaving a 2-inch border. Layer zucchini on top of ricotta mixture. Drizzle remaining garlicky olive oil over the zucchini. Fold border over the filling, pleating the edge to fit. The center will be open. Whisk egg with 1 tsp. water to make an egg wash, then brush on crust. Bake at 400 degrees until cheese is puffed, zucchini is slightly wilted and galette is golden brown, about 30 to 40 minutes. Sprinkle with basil and let stand 5 minutes before cutting and serving.