For the pastry:
* 3 cups all-purpose flour
* 1 1/2 teaspoons kosher salt
* 1 teaspoon baking powder
* 1/2 cup vegetable shortening
* 1/4 pound cold unsalted butter, diced
* 1/2 to 2/3 cup ice water
* 1 egg beaten with 1 tablespoon water, for egg wash
* Flaked sea salt and cracked black pepper