Shepherd's Pie

Method

1. 1

   Step 1

   Heat the oven to 400°F (200°C / Gas 6), with a rack in the upper-middle position. Set a 9-inch (23 cm) square, approximately 2½-quart (2.4-litre) baking dish on a rimmed baking sheet to catch any drips.

2. 2

   Step 2

   Place the potatoes in a large saucepan and cover with cold water by 1 inch (2.5 cm); add 1 tbsp salt. Bring to a boil over high heat, then reduce to a steady simmer and cook for 15–20 minutes, until a knife slides through the potatoes without resistance.

3. 3

   Step 3

   Meanwhile, heat a 12-inch (30 cm) deep frying pan over medium-high heat. Add the lamb and cook for 8–10 minutes, breaking it into small pieces with a wooden spoon, until no pink remains and some edges are browned. Spoon off excess rendered fat, leaving about 1 tbsp in the pan.

4. 4

   Step 4

   Reduce the heat to medium and add the onion and carrots to the lamb. Cook for 7–8 minutes, stirring regularly, until the onion is softened and translucent. Stir in the tomato paste and cook for 1 minute, then sprinkle over the flour and stir for another minute.

5. 5

   Step 5

   Gradually stir in the stock, scraping up the browned bits from the bottom of the pan, then add the Worcestershire sauce, thyme, ¾ tsp salt and ¼ tsp pepper. Bring to a gentle simmer and cook uncovered over medium-low heat for 12–15 minutes, stirring occasionally, until the carrots are tender and the gravy thickly coats the lamb. Stir in the frozen peas, cook for 2 minutes, then remove from the heat.

6. 6

   Step 6

   Drain the cooked potatoes thoroughly and return them to their saucepan over low heat for 1–2 minutes, shaking gently, until excess moisture has evaporated. Remove from the heat and mash until smooth. Warm the milk with 3 tbsp of the butter in a small saucepan over low heat for 2–3 minutes, until the butter melts, then gradually beat into the potatoes with the remaining ¾ tsp salt and ¼ tsp pepper.

7. 7

   Step 7

   Spoon the lamb filling into the baking dish and spread it into an even layer; it should be moist but not swimming in liquid. Let it stand for 5 minutes so the surface firms slightly before adding the mash.

8. 8

   Step 8

   Dollop the mash around the edges of the filling first, then across the centre. Gently spread it to meet the sides of the dish, sealing in the filling without pressing the potatoes down into it. Rake the surface with a fork to create ridges and dot with the remaining 1 tbsp butter.

9. 9

   Step 9

   Bake for 25–30 minutes, until the potato ridges are golden and the filling bubbles around the edges. Check that the centre reaches at least 165°F (74°C) on an instant-read thermometer. For a deeper golden top, finish under a hot broiler / grill for 2–3 minutes, watching closely and using a broiler-safe dish.

10. 10

    Step 10

    Leave the pie to rest for 10 minutes before serving so the filling settles and is easier to spoon out. Divide into six portions, serving each with both the fluffy potato topping and the lamb filling.