Lingonberries, also known as cowberries, are jewel-like berries rich in antioxidants and vitamins. Most often they are used in jams which can be very sweet to compensate for their natural tartness, so I try to use the real article if I have it, but then I don’t mind their sour, zingy flavour. If you are lucky enough to find frozen lingonberries from a specialist supplier, this is a great use for them. Of course, you can simply use lingonberry jam or substitute the berries for fresh or frozen cranberries. This breakfast is based on a kind of potato cake called råraka or raggmunk, which is normally served for dinner or lunch with bacon or sometimes whitefish roe, red onion and sour cream. I personally think it makes an excellent breakfast fritter for a lazy weekend brunch.