In a medium saute pan, heat olive oil over medium heat. Add the onions and garlic cook until tender and fragrant.
Add the pork and cook until no longer pink and browned. Add the chicken stock and simmer until liquid has evaporated.
Remove from the heat and add the cream cheese and Monterey jack cheese.
To make the empanadas, preheat oven to 350ยฐF.
On a floured surface, place one sheet of puff pastry. Roll the puff pastry sheet out to be slightly larger (12×18).
Using a round cutter (3 to 4 inches); cut into 8 rounds.
Place 1 tablespoon of filling into each round. Using your finger, dip into water and go around the edge of the circle. Fold in half to make a moon shape and to seal crimp the edges with a fork.
Place the empanadas on a prepared baking sheet with cooking spray. Whisk together one egg and water and brush over the empanadas. Place in the oven and bake for 15 minutes or until golden brown.