►Combine flour, salt, and baking powder in the bowl of a food processor. Add chèvre and butter. Pulse until mixture is crumbly. Add ice water and pulse until dough just comes together. Turn dough out onto plastic wrap, shape into a disk, wrap tightly and chill for 2 hours.

►Place dried mushrooms in a bowl with warm water and let steep 20 minutes. Use a slotted spoon to remove mushrooms and chop finely.

►Melt butter and olive oil in a large skillet over medium heat. Add reconstituted and fresh mushrooms and onions to skillet, stir to coat in fat, and cook until tender, 6-7 minutes. Add porcini or kosher salt, thyme, and cayenne and stir to combine. Sprinkle flour over mushroom mixture. Stir to combine, and cook, stirring constantly, for 2 minutes. Remove from heat and stir in crème fraîche. Cool to room temperature and move to refrigerator to chill 1 hour.

►Preheat oven to 450° F. Beat egg with salt and 1 teaspoon warm water.

► On a floured surface, roll dough to ⅛-inch thick. With a floured 3-inch biscuit cutter, cut out as many circles as possible. Place 1 teaspoon of mushroom mixture onto each piece of dough. Brush edges of circles with egg wash. Fold dough over filling. Use the tines of a fork to firmly press edges together. Prick tops of turnovers with the fork.

►Place turnovers on baking sheet lined with parchment paper. Brush tops with egg wash. Bake 12-14 minutes until golden.