Shepherd’s pie with sweet potato

Heat a saucepan lightly sprayed with oil. Cook ¼ brown onion (finely chopped), ¼ carrot (finely chopped) and ¼ celery stick (finely chopped) until softened. Add 100g lean lamb mince and cook until browned. Add ½ cup beef stock, 1 tsp Worcestershire sauce and ½ tbs tomato paste. Simmer until vegetables are tender. Add ½ cup canned cannellini beans (rinsed, drained) and cook until heated through. Mash 75g steamed sweet potato and 75g steamed potato with 2 tbs skim milk until smooth. Season well. Spoon meat mixture into a small ovenproof dish and top with mash. Bake in oven preheated to 180°C or 160°C fan-forced until golden. Serve with steamed green vegetables.