Ingredients

• 1 tbsp sunflower oil
• 1 large onion, chopped
• 2-3 medium carrots, chopped
• 500g pack lamb mince
• 2 tbsp tomato purée
• large splash Worcestershire sauce
• 500ml beef stock
• 900g potatoes, cut into chunks
• 85g butter
• 3 tbsp milk

Instructions

1. Heat the oil in a medium saucepan, then add the onion and carrots for a few minutes. When they are soft, turn up the heat, crumble in the lamb and brown.
2. Pour off any excess fat. Add the tomato purée and Worcestershire sauce, then fry for a few minutes. Pour over the stock, bring to a simmer, then cover and cook for 40 minutes, uncovering halfway.
3. Meanwhile, heat the oven to 180°C (fan 160°C) then make the mash. Boil the potatoes in salted water for 10-15 minutes until tender. Drain, then mash with the butter and milk.
4. Put the mince into an ovenproof dish, top with the mash and ruffle with a fork. The pie can now be chilled and frozen for up to a month. Bake for 20-25 minutes until the top is starting to colour and the mince is bubbling through at the edges.

Baking from frozen

To bake from frozen, cook at 160°C (fan 140°C) for 1 hour to 1 hour 20 minutes until piping hot in the centre. Flash under the grill to brown, if you like. Leave to stand for 5 minutes before serving.