1 large brown onion, finely chopped
500g lean beef mince
1 tablespoon cornflour
3/4 cup beef stock
3/4 cup tomato sauce
2 tablespoons Worcestershire sauce
1 tablespoon barbecue sauce
1 teaspoon Vegemite
2 sheets frozen, ready-rolled shortcrust pastry, thawed
2 sheets frozen puff pastry, thawed
1 egg, beaten
1 tablespoon olive oil