The original recipe is one of my favorites and a go to whenever Jerusalem artichokes are in season. But this year I had a new challenge, as my friend became vegan I decided to make a different version of this fabulous gratin. I used purple potatoes, for their beautiful color, Jerusalem artichokes (also known as Sunchokes), shallots and pre cooked and packaged chestnuts. To replace the milk, cream and cream fraiche I used my new favorite creamer: Cashews! For the best cashew cream I soak them over night in water, and then puree to a smooth "milk", but if you are pressed for time place a handful (about 1/2 a cup) of raw cashews in a bowl of hot water, replace the water as they cool down, or keep on a low simmer for an hour - two. The nuts are ready when they are soft and juicy, then you can puree them in a blender. start with a little water and add more if needed, you want it to be thick, not runny.
1/2 lb. medium potatoes,1/2 lb. Jerusalem artichoke, 1 cup chestnuts (cooked and peeled), 3 shallots,4 sprigs of thyme, 1/2 cup cashew cream (see instructions below), paprika, salt, pepper, juice of half a lemon and bread crumbs.
To make the cashew cream, soak 1/2 cup of raw cashews in warm water for at least 4 hours, drain them, reserving the liquid and pulse, together with half the liquid until smooth, use more liquid if needed. you can store any leftover cream in the fridge for up to 4 days. for this recipe, mix in some nutmeg into the finished cream.
pre heat the oven to 375 start by slicing all vegetable as thin as you can, then mix all ingredients but bread crumbs in a large bowl.adjust seasoning and layer in the dish you intend on using for baking. if you want to make distinct layers, you can mix the cashew cream in as you layer the vegetable, make sure it gets all the way in between the pieces and layers.sprinkle crumbs on top, cover and bake for 35 min, remove cover and bake about 15 min more or until golden in color. let the gratin cool down a little before digging in.