Peel the potatoes, before slicing them widthways as thinly as you can. Place them in a bowl, covered in cold water. Leave them to soak until you need them, to get rid of the starch, changing the water a couple of times.
Heat a drizzle of oil in a large non-stick pan that can be used on the hob and under the grill. (Don’t worry if you don’t have one, you can transfer it to an ovenproof dish before baking)
Add the sliced bacon and fry for 3 minutes, turning regularly until starting to colour.
Add the leeks to the pan and fry for another 3 minutes, stirring occasionally until the leeks are beginning to soften.
Remove the bacon and leek from the pan and set aside.
Add the chicken thigh to the same pan and fry for 3-5 minutes on a medium heat until no longer pink. Drain off the excess fat.
Heat the oven to 200C fan / 425F / Gas Mark 7
Add the flour to the pan and on the heat, stir until the chicken is coated, the flour has disappeared and the mixture is sizzling a little.
Add half the stock to the pan and stir until it comes to the boil and thickens.
Add the other half of the stock and do the same.
Stir in the cream, the bacon and leek and the chopped herbs. Season with salt and pepper. Mix until combined.
If your pan isn’t ovenproof, this is the point you can transfer the filling to a baking dish.
Drain the potatoes. Pat the slices dry with kitchen roll. Add them to the top of the filling, slightly overlapping and brush with melted butter.
Bake in the oven for 15 minutes. Top the hotpot with a handful of grated cheese, before returning to the oven for another 20-25 minutes or until the potato is soft and the top is crisp and golden brown.