1. Preheat the oven to 200C, 400F, Gas Mark 6. Peel the
potatoes and slice very thinly - no thicker than 3mm/1/8th of
an inch. Using a mandoline will make this easier.
2. Take four pieces of parchment each measuring about 30cm/12 inches
square, fold each piece in half then cut out a heart shape as shown
in the picture below.
3. Open up the parchment shapes, use some of the butter to
grease one half of each, then place the potatoes in layers on each,
overlapping them and seasoning each layer with salt and pepper, placing them close to the fold but making sure you leave a 5cm/2-inch
border along the edges.
4. Divide the sliced leeks between the parcels, placing them on top
of the potatoes, season with salt and pepper, dot with the remaining
butter and sprinkle with parsley.
5. Fold over the top of each parcel, line up the edges,
then fold over the edges to completely seal the parcels. See picture below.
6. Place the packages on a baking sheet, and bake for 20 minutes until the
puffed up and browning. Serve immediately. end of instructions