Known as chip gratin in my house, this is the most fabulous potato bake, and an indispensable part of Christmas celebrations in Sweden: the potatoes are cut as if you were making French fries, then layered up in a dish with onions that you’ve cooked in butter until soft, along with a couple of tins of Swedish ansjovis, with cream and milk (or all cream, if you prefer) before being topped with breadcrumbs (although I must admit I forgot to add them for this photograph!) and butter, and baked. As for these ansjovis, these are not — as you might think — anchovies, but sprats that come in a spicy, sweet brine, which give them a light pickled flavour. If you can’t get hold of them, then you can best replace them by chopping up a couple of pickled herrings. I should also tell you that for my fishphobic family, I simply forgo this element, and stir three tablespoons of grated parmesan into the cream and milk instead. I wouldn’t dare serve it like this to a Swede, but I can vouch for its (inauthentic) deliciousness this way. But if you can get hold of the Swedish ansjovis, do; you can find them online or at some Ikea branches. For US cup measures, use the toggle at the top of the ingredients list.