Sweet potato shepherd's pie

Method

• Step 1
  Place flour in a bowl. Add lamb. Toss to coat. Heat 1 tablespoon oil in a large heavy-based, flameproof casserole dish over medium-high heat. Add half the lamb. Cook, stirring, for 4 to 5 minutes or until browned all over. Transfer to a bowl. Heat 1 tablespoon oil in dish. Add remaining lamb. Cook, stirring, for 4 to 5 minutes or until browned all over. Transfer to bowl.
• Step 2
  Reduce heat to medium. Heat remaining oil in dish. Add onion. Cook, stirring for 3 minutes or until softened. Add cinnamon, curry leaves and garlic. Cook, stirring for 1 minute or until fragrant. Add paste. Cook, stirring, for 3 minutes or until fragrant. Return lamb to pan. Stir to coat.
• Step 3
  Add stock and tomato. Cover, bring to the boil. Reduce heat to low. Simmer for 1 hour. Add eggplant. Simmer, covered, for 1 1/2 hours or until lamb is tender. Add lentils. Season with salt and pepper. Simmer, uncovered, for 5 to 10 minutes or until lentils are heated through. Stir in coriander.
• Step 4
  Meanwhile, make sweet potato topping Preheat oven to 200°C/180°C fan-forced. Cook sweet potato and potato in a large saucepan of boiling water for 10 to 12 minutes or until tender. Drain. Return to pan. Mash until smooth. Season with salt and pepper.
• Step 5
  Spoon lamb mixture into a greased, 8-cup capacity rectangular baking dish. Top with mash and dot with butter. Bake for 40 minutes or until golden. Serve.