Preheat oven to 220°C (200°C fan forced) lightly spray a baking tray with oil. OR preheat an air fryer to 205° C.
Roughly chop the shredded beef and place in a bowl, add the cheese and mix well.
Using a 10 cm round cookie cutter, cut five rounds from each pastry sheet. Lightly moisten outer edge of a pastry round with water and place about one tablespoon of filling in the centre. Fold pastry in half over filling. Use fingers to pinch and pleat the pastry edges or use a fork to seal edges together. Repeat with remaining filling and pastry.
Place empanadas on prepared baking tray and brush with egg wash. Bake for 15 minutes or until puffed and golden. OR Place empanadas into air fryer and lightly brush with egg wash. Air fry for 5 -8 minutes or until puffed and golden brown (time will depend on appliance). Serve with sour cream.