Melt the Clover in a large pan and gently fry the onion, leek, carrots and garlic for 15 minutes until soft. Add the mushrooms and thyme and continue to cook for 5-10 minutes until the mushrooms are soft and any excess liquid has evaporated.

Pour in the red wine and tomatoes and add the lentils, stock cube, soy sauce and sugar. Bring up to a simmer and cook for about 20 minutes then season to taste with plenty of salt and pepper.

Preheat the oven to 190C/375F/gas mark 5.

To make the sweet potato topping, boil the sweet potatoes in a large pan of salted water until tender, drain well then return to the pan.

In a small pan, melt the Clover, add the garlic and cook gently for about 5 minutes until the garlic begins to turn golden, pour the garlic butter into the potatoes then mash them and season with salt and pepper.

Transfer the filling to a large ovenproof dish and spread the mash over the top (or get fancy like I did and pipe it on using a piping bag fitted with a large star nozzle); sprinkle over the cheddar (at this point the pie can be refrigerated for up to a couple of days). Bake for 30-40 minutes until golden and bubbling.