- Rinse 1 cup (128g) of lentils under cold water. Then cook in simmering water for 25-30 minutes until tender. Drain and set aside for later.
- Finely chop onion and carrot. Heat a drizzle of oil in a large frying pan over medium heat. Add onion and carrot and cook for 5 minutes or until soft and golden. Push mixture to the side of the pan and add mince. Cook, breaking up lumps, for 5 minutes or until browned.
- Add lentils, stock powder, ¼ cup water, tomato paste and simmer for 10 minutes. Squeeze excess moisture from spinach and stir into beef mixture along with the oregano. Spoon into a baking dish.
- Meanwhile, cut potatoes into 3cm pieces and cook in lightly salted, boiling water for 15 minutes until tender. Add butter and milk and mash with a fork or potato masher until smooth. Sprinkle with cheese (optional, see tip).
- Heat grill. Spoon mashed potato onto beef mixture and grill until golden.
- Serve with steamed green beans.
TIP: Sprinkle mash with grated cheese before grilling.