Heat the oil in a heavy saute pan over medium-high heat. Add the ground beef chuck and cook until browned, about 7 minutes. Season with the salt and pepper. Add the olives, raisins, carrots and onions and saute for just a couple minutes until softened. Add the tomato puree and simmer for 10 minutes. Turn the heat off and cool to room temperature before filling the empanadas.
Grease a large baking sheet with some nonstick cooking spray. Unfold one sheet of puff pastry onto a lightly floured surface. Using a floured rolling pin, roll the pastry out to a 1/4- to 1/8-inch thickness. With a knife, cut out 4 equal squares measuring 4 1/2-by-5 1/2-inches. Add 2 tablespoons of the cooled beef mixture to the center of the square. Brush the edge of each square with some egg wash and fold to shape into triangles. Crimp the edges with a fork. Transfer the empanadas to the prepared baking sheet and brush them with the remaining egg wash. Bake until golden brown, about 25 minutes.