Peel, wash and chop the potatoes. Cover and cook in boiling salted water for about 20 minutes. Clean the leek, cut into 14-15 cm long pieces and wash. Cook in boiling salted water for 6-8 minutes.
Pour off, rinse with cold water and drain. First wrap 1 slice of bacon and 1 slice of cheese around each leek. Wrap another 1 slice of bacon around each cheese. Drain the potatoes and let them drain.
Add double cream and milk and mash everything to a puree. Season to taste with salt and nutmeg. Put the puree into a greased casserole dish. Spread sticks on top. Wash the thyme, dab dry, strip and sprinkle over the casserole.
Bake in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-25 minutes until golden brown.