Preheat the oven to 200°C.
Fry onions and carrots in sunflower oil for 8 minutes until softened.
Add beef mince and cook until browned all over.
Stir in the flour and cook for a few minutes.
Gradually add beef stock, water, tomato purée, and bay leaves.
Simmer covered for 30 minutes until mince is tender and sauce thickens.
Season with Worcestershire sauce, salt, pepper, and parsley.
Spoon the beef mixture into ovenproof dishes.
Boil potatoes in water for 15 minutes until soft.
Drain potatoes and mash with butter and milk until smooth.
Spread the mash over the beef and create patterns with a fork.
Bake for 25 minutes until the topping is golden-brown.