Preheat oven to hot 220C (425F). Line, or lightly grease, 2 baking trays.

Place the eggs in a small saucepan, cover with water and bring to the boil. Boil for 10 minutes, then drain and cool in cold water for 5 minutes. Peel and chop.

Combine the egg, olives, ham and Cheddar in a large bowl.

Cut out five 10cm rounds from each pastry sheet (15 in total). Place 1 tablespoon of filling onto the centre of each circle. Fold the pastry over, to create a half-circle, and seal the edges.

Place the empanadas on the prepared trays about 2cms apart. Brush with the egg yolk and bake for 15 minutes, or until puffed and dark golden in colour.

You may need to swap the trays around at the 10 minute mark to cook evenly. If they start to brown too much loosely cover with foil. Serve hot.