Sweden.

The potato arrived late and then took over completely. Before the nineteenth century the Swedish staple was grain — porridge, gruel, and flatbread baked twice a year in enormous batches — but once potatoes took hold they became the default carbohydrate at nearly every warm meal, and a good half of the classic dishes are really potato dishes with something on the side. They appear boiled and pressed under meatballs, grated raw into raggmunk batter, sliced into matchsticks and drowned in cream for Janssons frestelse, and diced small and fried hard for pyttipanna. Learning to tell a floury potato from a waxy one is not a refinement in this kitchen; it is the difference between a dish working and failing.

The second organising idea is the sweet-sour-salt triangle. Almost every savoury Swedish plate carries a sharp or sweet counterweight: lingonberry jam, pickled cucumber, pickled beetroot, a sweet-strong mustard, or the sugar folded quietly into brines and cured fish. To an outsider it can read as odd — jam with meat, sugar in a herring pickle — but it is the same instinct that puts apple sauce next to pork elsewhere, simply applied more consistently and with more confidence.

Spicing is small and stubborn. Allspice is the flavour that makes a Swedish stew Swedish; dill is used by the fistful with fish and potatoes rather than as a garnish; white pepper is preferred to black in pale cream sauces; caraway goes into bread, cheese and aquavit. Cardamom belongs to the baking side, and Sweden uses staggering quantities of it — the buns, the doughs and the coffee-table cakes are built on freshly ground green cardamom, and using the pre-ground powder is the single fastest way to make Swedish baking taste flat.

Meal structure follows the calendar and the clock. Weekday food is husmanskost: one hot plate, potatoes, a pickle, and no courses. Thursday, by a tradition several centuries old, is yellow pea soup with mustard followed by pancakes. The great feasts are buffets — the julbord at Christmas, the midsommar table with new potatoes and cured herring, the August crayfish party eaten outdoors under paper lanterns — where you go up in rounds, cold dishes first, and nobody piles everything on one plate.

Regionally the country stretches far enough to hold different kitchens. The far north cooks reindeer, cloudberries, freshwater fish and the fermented Baltic herring that outsiders find alarming; the west coast is a shellfish coast; the deep south, closer to Denmark than to Stockholm, is richer and goose-eating, with the country's best farmland behind it.