Beef and Mushroom Empanada

 For the dough:
 3 cups (450 grams) all-purpose flour
 ¼ teaspoon salt
 1 cup /2 sticks (226 grams) unsalted butter, cut into cubes and chilled
 1 egg, room temperature
 4 tablespoons water

For the filling:
 1 tablespoon oil
 2 cups (250 grams) portobello mushrooms, finely chopped
 1 pound (453 grams) ground beef
 1 small onion, finely chopped
 1 large carrot, finely chopped
 ¾ teaspoon salt
 ½ teaspoon freshly ground black pepper
 2 garlic cloves, finely chopped or grated
 1 teaspoon ground cumin
 1 teaspoon dried oregano
 1 cup (225 grams) tomato puree

Make the Dough:
1. Add the flour, salt and butter to a large bowl. Using your fingertips (or a pastry cutter) rub the butter and flour until it resembles breadcrumbs. Add the egg and then drizzle in the water and mix using a fork until the it starts to come together and holds together when pressed in your hand. You may not need all of the water.
2. Turn out onto a floured surface, form into a smooth ball, flatten and wrap with plastic wrap. Refrigerate for 30 minutes.
Make the filling:
1. Add oil to a large sauté pan over medium heat until the oil ripples. Add the mushrooms and cook, stirring often until the start to brown. Add the beef, onion, carrot, salt and pepper and cook while breaking up the meat until browned. Stir in the garlic, cumin and oregano and cook for 2 minutes. 
2. Stir in the tomato puree and simmer for 5 minutes until thickened.
3. Remove from the heat, transfer to a bowl and allow to cool to room temperature.
4. Line a large baking sheet with parchment paper.
5. Preheat oven to 350°F/180°C.
6. Roll the dough to 1/8 inch thick. Cut out 6 inch circle. Place a small amount of meat into center of dough circle, brush egg wash around edges and fold in half. Press edge with a fork to seal.
7. Line them all up on the baking sheet and brush all over with egg wash.
8. Bake for 25-30 minutes or until golden brown.