Potato and Beef Empanadas

Name: Potato and Beef Empanadas
Ingredients: 4 cups Gold Medal™ Organic All-Purpose Flour; 1/2 teaspoon baking powder; 1 1/2 teaspoons sea salt; 1 1/2 cups cold butter, cut into pieces; 1 1/4 cups cold buttermilk; 1 lb ground beef; 2 cups cubed (1/2-inch) peeled potato (1 large); 1/4 cup chopped onion; 1 teaspoon finely chopped garlic; 1 1/2 tablespoons finely chopped jalapeño chile, seeded; 1 can (10 oz) diced tomatoes and green chiles, undrained; 1/2 teaspoon red pepper flakes; 1 teaspoon sea salt; 1 cup shredded Monterey Jack cheese (4 oz); 1 egg, slightly beaten