Make filling: Combine the beef, pork, bell pepper, garlic, green onions, salt, and pepper in a large heavy skillet over medium-high heat. Cook, stirring, until the meat is brown and all pink has disappeared. Remove from the heat, sift the flour over the meat mixture, and stir until blended. Drain the mixture in a colander and cool completely.
Make pastry: Sift together the flour, salt, and baking powder in a large bowl. With a pastry knife cut the shortening into the flour until small pea-sized balls form. Stir in the egg and milk until a soft dough forms. Divide the dough into 16 small balls of equal size. Working with 1 ball of dough at a time, turn onto a lightly floured work surface, and with a floured roller, roll dough into a 6 1/2-inch by 13-inch rectangle. Cut dough into two 6-inch diameter circles using a saucer as a guide. On each circle of dough, place 2 heaping tablespoons of the filling in the center, dampen the edge of the circle with wet fingertips, fold the dough over the filling aligning edges, and crimp the edge with the tines of a fork dusted with flour. Lay the pies in a single layer on a sheet of waxed paper. Repeat with remaining balls of dough.
Heat about one and one-half inches of vegetable oil to 325ºF in a large, heavy skillet heat. Fry 4 pies at a time in the hot oil until golden brown, about 3 minutes first side, 2 minutes second side. Remove the pies from the skillet and drain on paper towels. Serve warm.
Freeze any un-fried pies in a single layer on waxed paper lined baking sheets. Do not thaw frozen pies before frying.
Makes about 32 pies