Cheesy leek & bacon stuffed jackets

Preheat the oven to 220ºC/200ºC fan/gas 7. Put the potatoes on a baking tray, prick all over, then bake for about 1 hour, or until tender, turning halfway through. Meanwhile, tip the lardons into a frying pan and cook over a low-medium heat until they have released lots of fat and look crisp. Use a slotted spoon to remove, leaving the fat in the pan. Add the butter and leeks, season and cook gently for 10-15 minutes until soft, then set aside.

Halve the potatoes lengthways and scoop the flesh into a mixing bowl. Put the skins back on the tray and into the oven for 5-10 minutes to crisp up. Meanwhile, mash the potato flesh and stir in the lardons, leeks, most of the cheese, the crème fraîche, mustard and tarragon; season.

Scoop the mixture into the skins and sprinkle over the remaining cheese. Bake for 5-10 minutes until bubbling and melted.