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, spread or pipe the potato mixture on top
Then 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 veg, such as peas and broccoli