Sweet potato mash pie

Serves 6 Prep 25 mins Cook 1 hr 20 mins £1.20 a portion 434 kcals, 12g fat, 4g sat. fat, 17g sugar

1 tbsp rapeseed oil 2 onions, finely chopped 2 garlic cloves, chopped 2 carrots, grated or finely diced 2 tbsp fresh thyme leaves 400g pack extra-lean minced

lamb or beef 85g red lentils 350g swede, diced 2 tbsp plain flour 750ml reduced-salt beef stock 200ml red wine 350g potatoes, diced 650g sweet potatoes, diced 150g pot 0% plain probiotic yogurt generous grating of nutmeg green vegetables, to serve

Heat the oil in a large pan, then fry the onions for 6 mins until starting to turn golden. Add the garlic, carrots and thyme, and cook for 4 mins more. Stir in the mince, breaking it up with the spoon. When it has turned brown, add the lentils and swede with the flour. Cook for 1-2 mins, then gradually add the stock and red wine. Cover and simmer for 35- 40 mins.

Meanwhile, boil all the potatoes for 15-20 mins until tender, then drain and mash with the yogurt, nutmeg and black pepper. Spoon the meat mixture into a 2-litre ovenproof dish and spread or pipe the potato mixture on top. Grill until the topping starts to brown. (If making ahead, reheat in the oven at 180C/160C fan/gas 4 for 45 mins.) Serve with green vegetables, such as peas and broccoli, if you like.