Heat 1 tbsp sunflower oil in a medium saucepan then soften 1 chopped onion and 2-3 chopped carrots for a few minutes.
When soft, turn up the heat, crumble in 500g lamb mince and brown, tipping off any excess fat.
Add 2 tbsp tomato puree and a large splash of Worcestershire sauce, then fry for a few minutes.
Pour over 500ml beef stock, bring to a simmer, then cover and cook for 40 minutes, uncovering halfway.
Meanwhile, heat the oven to 180c/fan 160c/gas 4, then make the mash. Boil the 900g potato, cut into chunks, in salted water for 10-15 minutes until tender. Drain then mash with 85g butter and 3 tbsp milk.
Put the mince into an ovenproof dish, top with the mash and ruffle with a fork.
Bake for 20-25 minutes until the top is starting to colour and the mince is bubbling through at the edges.
1 tbsp sunflower oil
1 large onion, chopped.
2-3 medium carrots, chopped.
500g lamb mince.
2 tbsp tomato purée.
Large splash Worcestershire sauce.
500ml beef stock.
900g potato, cut into chunks.
3 tbsp milk.