Step 1
To make the filling: Place pork in a large pot and cover with water. Add onion garlic salt oregano cumin and bay leaves. Bring to a boil reduce heat and simmer for 1 1/2 hours. While pork is cooking prepare dough.
Step 2
To make the dough: Sift together the flour masa harina baking powder and salt. Add the shortening to the dry ingredients and mix well. In a separate bowl beat together the egg and 1/2 cup milk. Make a well in the center of the dry ingredients. Add the egg mixture and stir with a fork until the dough comes together in a ball. Divide the dough into 16 even pieces and roll each piece into a ball. Place in a container cover and refrigerate.
Step 3
Preheat oven to 375 degrees F (190 degrees C).
Step 4
After the pork has simmered for 1 1/2 hours remove from liquid. Place pork in a baking dish and bake for 1 hour or until meat shreds easily with fork. Remove from oven (keep oven turned on) and shred into small pieces. Add salsa to shredded pork.
Step 5
Lightly grease a baking sheet.
Step 6
On lightly floured surface flatten a piece of dough with the palm of your hand. With a rolling pin roll out the dough to make a 5-inch circle about 1/8-inch thick. Place 2 to 3 tablespoons of filling in the center of the dough circle. Brush edges of dough with milk. Fold dough over filling. Pinch edges together. Crimp with fork to seal.
Step 7
Place on prepared baking sheet and repeat with remaining empanada dough. Leftover filling can be frozen or used in tacos tamales or burritos.
Step 8
Bake in preheated oven until golden about 20 minutes. Remove to rack and cool for about 5 minutes. Serve warm.