Divide pie crust into 12 balls. Place each ball between two sheets of parchment paper and with a rolling pin, gently flatten each ball into 5-inch diameter and ¼-inch thickness. Using a round biscuit cutter or an inverted bowl, cut into the dough by gently twisting to form circles with smooth edges. Trim excess dough.
On a flat work surface, lay dough circle and spoon about a heaping tablespoon of filling in the middle. Fold the bottom of the dough over filling and with fingers, press edges firmly. Using tines of a fork, press on sides of dough to firmly seal. Repeat with remaining dough and filling. On a lightly greased baking sheet, arrange prepared empanadas in a single layer and brush top with egg wash. Bake in a 375 F oven for about 25 to 30 minutes or until lightly browned. Allow to slightly cool for about 1 to 2 minutes and remove from baking sheet.
For the Crust:
Cut butter into cubes and freeze for about 1 hour. In a bowl, whisk together flour, sugar and salt and chill in the refrigerator for about 30 minutes.
Add butter to flour mixture. Cut the butter into the flour using a pastry blender or by pinching the fat into the flour mixture with hands. Work them together until resembling coarse cornmeal with pea-like, butter-speckled pieces.
Slowly drizzle water to the flour-butter mixture and with hands, mix until just combined. Gently gather dough and press into a ball. If the dough is too crumbly and does not hold together, add more water a tablespoon at a time. DO NOT ADD TOO MUCH LIQUID and DO NOT OVERWORK DOUGH. Wrap dough with plastic wrap and chill in the refrigerator for about 2 hours.
For the Filling:
In pot, heat oil over medium heat. Add onions and garlic and cook until translucent and fragrant. Add ground beef and cook, stirring occasionally and breaking to pieces with back of the spoon, for about 6 to 8 minutes, or until pink is gone from meat.
Add tomato sauce and water and bring to a boil. Lower heat, cover and simmer until meat is fully cooked.
Add potatoes, carrots, green peas and raisins. Continue to cook until vegetables are tender and liquid is reduced. Season with salt and pepper to taste. In a colander, drain excess liquid.