Based on a recipe from Nigel, this is hardly diet food, but it warms the cockles and used up lots of odds and ends from the fridge. Cut a medium peeled potato into small cubes and steam until tender. Meanwhile, gently sweat a couple of cleaned, sliced leeks in about 20g of butter until soft, but not browned. Turn off the heat and allow a dessertspoon of creme fraiche to melt through the leeks. Cool a little, then gently stir in the cooked potatoes, about 50g of strong cheddar cheese, and I added a couple of slices of ham that needed using up. Season well with black pepper. Unroll a sheet of ready-rolled puff pastry and place on a baking sheet. Spread the cooled filling on one half, leaving a centimetre border around the edge. Brush the exposed border with some milk and bring the other half of the pastry over, sealing the edges. Make a steam-hole in the top of the pie, brush with more milk, and cook at around 170C for 30 minutes or so until lovely and brown and crisp. Would serve 4 at a pinch we we devoured it between two. But we are pigs, after all.