To start, parboil 2/3 of the potatoes. Leave one third of them to continue to soften more and set the other aside. Leave one set of these potatoes unpeeled and peel the other.
For the hash browns - with the peeled batch, grate into a bowl of ice-cold water. Repeat with the remaining potatoes and then squeeze out all of the water and place in a clean bowl. To this add the beaten egg, the onion and season. Squeeze together in the shape you fancy, triangles or bar shapes are best. Fry in a knob of butter on a medium heat for 3-4 minutes on each side.
Dutchess - with the potatoes that have been left to cook further, drain and whilst still hot, carefully remove the skins. Put these through a ricer or mash, and add to the the butter and cream and season. Once completely
Smooth, this may take a while, place the mash into a piping bag with a star nozzle and on a lined baking tray, pipe into spiral peaks and place in a hot oven of 200, and bake until golden and crisp on the outside, around
20 minutes. Sliced baked - with the uncooked potatoes, thinly slice on the mandolin and in a greased ovenproof dish, layer up the slices of potato so they stand in the shallow dish.
You will need to fill this with the stock, around a cup, just enough to half-cover the potatoes. You can add anything else in your fancy, garlic, herbs and so on. Bake at 180 for 20 minutes.
Spiral fries - with the unpeeled batch of parboiled potatoes, place on the spiral cutter and using the cutter, spiral the potatoes. Deep fry and sprinkle with salt.