Scandinavian seeded crispbreads made with minimal flour, some salt, oil, water and sesame, flax, poppy and sunflower seeds (and a few aromatic ones too) are a crunchy, delicate platform for butter, cheese, pickled herring and anything at all savoury. They are a superb crunchy accompaniment to soup, too. Versions of knækbrød are eaten all over Denmark, Sweden and Norway and considered essential …