Scrub the potatoes, put them in a large saucepan, cover with cold water and bring to the boil. Turn the heat down to a simmer and cook for about 20 minutes or until the potatoes are tender when pierced with a fork.
Meanwhile, peel and chop the onion, Peel and crush the garlic. Grate the pecorino. Wash and chop the herbs. Rinse the lentils until the water runs clear.
PRE-HEAT OVEN TO 180˚C/160˚C FAN/GAS 4
Warm half the oil in a large pan. Add the onion, garlic and chopped herbs, sprinkle with a little salt. Cook on a very low heat for 5 minutes until you have a soft and fragrant mixture.
Stir in the minced meat and brown for 3-4 minutes, breaking up any clumps if necessary.
Add the balsamic vinegar, smoked paprika and a grating of nutmeg and continue cooking for a couple more minutes. Add the lentils, chopped tomatoes and tomato puree to the pan and stir well to combine.
Add 250ml of hot water to the pan, turn the heat down and simmer for 25 minutes.
Mash the potatoes and loosen with the remaining 2 tablespoons of olive oil. Season with a little salt.
Transfer the minced lamb to an oven dish and cover with the potato topping. Sprinkle with the grated pecorino and bake for 15 minutes until the top is golden brown.
Leave to stand for a few minutes before serving.
Recipe Notes
This traditional winter warmer makes a great-value, healthy family meal.
This dish freezes beautifully for up to 2 months. Freeze whole on the day you make it - or divide the pie into individual portions and freeze in ovenproof dishes for easy meals for one. For best results defrost the pie overnight then bake at 190˚C/170˚C FAN/GAS 5 for 30 minutes or until the topping is golden.