Shepherd's Pie

Ingredients

• 800g minced lamb (roughly 15% fat)
• 1.2kg floury potatoes such as Maris Piper
• 2 medium onions, finely diced
• 2 carrots, finely diced
• 2 celery sticks, finely diced
• 3 garlic cloves, crushed
• 2 tbsp tomato puree
• 2 tbsp plain flour
• 400ml lamb or beef stock
• 150ml dry red wine
• 2 tbsp Worcestershire sauce
• 2 tsp fresh thyme leaves
• 1 bay leaf
• 100g frozen peas
• 80g butter
• 100ml whole milk
• 60g mature Cheddar, grated
• 1 egg yolk
• 2 tbsp olive oil
• Salt and black pepper

Before you cook

• Peel the potatoes and cut them into even chunks about 5cm across.
• Finely dice the onions, carrots and celery, keeping the pieces roughly the size of the mince.
• Crush the garlic and strip the thyme leaves from their stalks.
• Grate the Cheddar and separate the egg yolk into a small bowl.

Steps

1. Set a wide heavy pan over high heat and add one tablespoon of olive oil.
2. Add half the minced lamb in a single layer and leave it undisturbed for three minutes so it browns rather than steams.
3. Break the lamb up with a wooden spoon and cook for another three minutes until it is deeply coloured, then lift it into a bowl.
4. Brown the remaining lamb the same way and add it to the bowl.
5. Lower the heat to medium, add the second tablespoon of oil and tip in the onion, carrot and celery.
6. Cook the vegetables gently for ten minutes, stirring now and then, until they are soft and sweet with no bite left.
7. Stir in the garlic and thyme and cook for one minute until fragrant.
8. Add the tomato puree and cook it for two minutes, stirring constantly, until it darkens to brick red.
9. Scatter over the flour and stir for one minute so it coats everything.
10. Pour in the red wine and scrape the base of the pan hard to lift every browned scrap.
11. Let the wine bubble for three minutes until it has reduced by half.
12. Return the lamb to the pan along with the stock, Worcestershire sauce and bay leaf.
13. Bring the pan to a simmer, then turn the heat low and cook uncovered for forty minutes, stirring occasionally.
14. Check the filling: it should be thick enough that a spoon dragged across the base leaves a clear trail. If it is loose, simmer another ten minutes.
15. Taste the filling and season generously with salt and pepper, then stir through the frozen peas and remove the bay leaf.
16. Tip the filling into a deep 2.5 litre baking dish and spread it level, then leave it to cool for twenty minutes.
17. Heat the oven to 200C fan.
18. Put the potato chunks in a large pan, cover with cold salted water and bring to the boil.
19. Simmer the potatoes for eighteen to twenty minutes until a knife slides through with no resistance.
20. Drain the potatoes thoroughly and return them to the dry pan over low heat for one minute to steam off surface moisture.
21. Mash the potatoes until completely smooth, or push them through a ricer for the finest texture.
22. Beat in the butter, then the milk, then the egg yolk, and season the mash well with salt.
23. Spoon the mash over the cooled filling in dollops and join them up gently so the meat stays underneath.
24. Drag a fork across the surface in long lines to raise ridges that will catch the heat and crisp.
25. Scatter the grated Cheddar over the top.
26. Bake for thirty to thirty-five minutes until the peaks are deep gold and gravy bubbles up at the edges.
27. Rest the pie for ten minutes before serving so the filling settles.