130g unsalted butter (100g for the Mashed Potato topping)
150g carrot, diced
180g onion, diced
6 garlic cloves, finely chopped
1 tsp thyme leaves
A large pinch of dried herbes de Provence
1 ½ tbsp flour
200g plum tomatoes, seeded, skinned and roughly diced
40g tomato purèe
400ml chicken stock
A large pinch of freshly ground black pepper
500g potatoes (Maris Piper, King Edward or Desiree), peeled
50ml warm milk
Cut the potatoes for the mash into rough 5cm chunks. Put them in a pan of cold, salted water, bring to a simmer and cook for 30 minutes. Drain well, then pass through a mouli, adding the butter. Put the potatoes back into the pan, season and add warm milk.
Place a large, shallow pan over a high heat. Add the oil and once it is hot, add the lamb mince. Spread it out evenly over the pan and leave it to cook for 3-4 minutes without stirring. When you see the meat beginning to colour around the edges, start to stir it and move it around the pan. Cook for another 5 minutes, adding half the salt and stirring every so often until the meat is golden all over. Tap the mince so it breaks down, then drain it in a colander set over a bowl to collect the oil.
Pour the oil back into the pan with butter. Add the diced carrot and the rest of the salt and cook on a low heat for 2-3 minutes, scraping all the sediment from the pan. Add the onion, garlic, thyme and dried herbs and cook for 3 minutes over a medium heat. Put the mince back in the pan with the flour. Cook this for a minute, then add the diced tomatoes, tomato purèe and stock and bring to a simmer.
Add the pepper and continue to simmer for 10 minutes. Pile the meat into a heatproof dish.
Place the cut potato into the cold water with 10g salt in a pan, place on to the heat and bring to a simmer turn the heat down and simmer for 30 minutes then tip the potatoes into a colander to drain really well.
Place the potato back in the pan and dry out on a low heat for 1 minute then add the butter, salt,pepper and the warm milk while you mash the potato.
Cover the Shepherd’s Pie mix with potato. Put the dish under a hot grill for 3 minutes to colour the top and the pie is ready.