Sweden — first printed recipe in the 1940s; associated with the Swedish smörgåsbord tradition; the name's Jansson is disputed between multiple historical figures
A Swedish anchovy and potato gratin with layered ambition — julienned raw potatoes layered with caramelised onion and Swedish ansjovis (a spiced, salt-cured sprat, not Italian anchovies), then baked under a blanket of heavy cream until the potato is tender, the cream has absorbed into a rich, savoury sauce, and the top is golden-brown. The name's mythology involves a 19th-century Swedish opera singer caught eating fish gratin despite his professed vegetarianism. The key distinction is the Swedish ansjovis — which is sweeter, more lightly brined, and spiced with allspice and cloves — versus Italian anchovies, which would make the dish too salty and lack the spiced sweetness. The cream is added in two stages to regulate absorption.
Served as a side dish at julbord (Christmas buffet) and smörgåsbord; also a standalone winter dinner with bread; pairs with cold light lager or akvavit; the sweetly spiced fish note is an acquired taste that rewards patience
{"Use Swedish ansjovis (spiced sprats), not Italian anchovies — the saltiness and spice profile are completely different; Italian anchovies make the dish too intense and salty","Add cream in two stages: pour half before baking, add the second half halfway through — this prevents the cream from being absorbed before the potato is cooked","Julienne the potatoes finely (3–4mm) — thick chunks extend baking time and the cream reduces before the potato is tender","Bake covered for the first 20 minutes, then uncovered — the cover traps steam that helps cook the potato; uncovered finishing browns the top"}
Rinse the potato julienne in cold water and pat dry before layering — this removes excess surface starch that would thicken the cream sauce prematurely and produce a gluey texture. The top layer of cream, added halfway through baking, should include a tablespoon of the ansjovis brine — this distributes the spiced sweetness more evenly through the cream without adding additional solid fish.
{"Adding all cream at once — early addition causes cream to reduce and separate before the potato is cooked through","Using Italian anchovies — the dish becomes aggressively salty; Swedish ansjovis are critical to the dish's character","Skipping the caramelised onion — raw onion or under-cooked onion has a sharp bite that conflicts with the delicate cream sauce","Over-salting — the ansjovis contribute significant salt; taste before adding any additional salt"}