Saute the garlic in a medium pan over medium heat in oil for 1 minute, then add the onion and cook until translucent. Saute in the beef and cook until no longer pink or for 5 minutes. Season with salt and pepper. Add the potatoes and raisins. Splash worcestershire sauce 2 times stirring and mixing everything together. Thicken the sauce with the cornstarch dissolved in 1/4 cup water.
To form dough
Put pastry on a lightly floured board. Cut into 16 pieces. With the palm of your hands, shape each piece into a small ball. Roll each small ball with a rolling pin into a round thin flat dough until about 5" in diameter. Repeat the process.
Fill the center of the flat dough with 1 tablespoon beef filling. Bring one side of the dough to the other side of the pastry and start pressing both edges together toseal them. Now you either can either crimp the edge with the tines of a fork or foldwith your fingers. Repeat the process. With practice you can master thesealing and folding with your hands or crimping with the tines of a fork, whichever you prefer.
Preheat oven to 425 degrees Fahrenheit. On a greased or parchment lined cookie sheet, arrange empanadas about an inch apart. Brush the top with egg wash. Poke each Empanada with a fork to create a vents. Bake at 425 degrees F for 10 minutes, then lower the temperature to 400 degrees F and bake for 15 minutes more. Let cool.