1. Heat olive oil in a large saucepan and gently cook the finely chopped onion, crushed garlic and chopped carrots until onion is tender. Increase the heat and add the beef mince to the pan, tossing at times until it is golden brown.
2. Add the finely chopped mushrooms, dried oregano, tomato paste, beef stock, 2 cups of water and salt and freshly ground black pepper to taste.
3. Bring to the boil and simmer for 1¼ hours. Thicken with flour mixed to a paste with ¼ cup cold water. Allow mince to cool and then refrigerate until required.
4. Preheat oven to 200C. Line a 26cm round pie dish with shortcrust pastry. Stir 2cm cubes of tasty cheese through the cooled mince and then spoon into the pastry base.
5. Sprinkle with mozzarella cheese and then top with puff pastry, sealing edges. Brush with egg yolk or milk if desired and then bake for 30 minutes until puffed and golden.
Recipe from eatwell.co.nz