Few Nordic dishes stir as much nostalgia in Sweden and Finland as Jansson’s Temptation (Janssons frestelse). Think of it as the Scandinavian cousin of a potato gratin: layers of match‑stick potatoes, sweetly sautéed onions, spiced sprat fillets and lashings of cream, baked until bubbling and golden. It shows up on Sweden’s Christmas “julbord,” but it’s just as welcome as an everyday lunch or midnight snack – especially because this humble casserole comes together with minimal fuss. But before you head for the nearest tin of anchovies, read on. In Sweden “ansjovis” refers to sugar‑salted and spiced sprats (Sprattus sprattus), not the Mediterranean anchovies (Engraulis encrasicolus) found in most supermarkets. This translation mix‑up has led countless recipes astray.
In this post we’ll dive into the origins of Jansson’s Temptation, decode its ingredients, walk through a fool‑proof recipe and explore modern twists. Whether you’re planning a yuletide smörgåsbord or looking for a cosy weekday lunch, this classic casserole delivers comfort in every creamy forkful.
What is Jansson’s Temptation?
Jansson’s Temptation is essentially a potato gratin with a Nordic twist. Thin batons of potato are layered with sautéed onions, topped with fillets of spiced sprats and drenched with cream before baking. In Sweden these sprats are tinned in a sweet‑savory brine containing sugar, salt and warm spices such as allspice and cloves. They are labelled ansjovis in Swedish, but they are not anchovies – true anchovies (Engraulis encrasicolus) are called sardeller. Because the word “anchovy” often gets mistranslated, many English‑language recipes substitute Mediterranean anchovies, resulting in an overly fishy, salty dish. Using genuine Swedish sprats gives a milder, slightly sweet flavour that melts into the potatoes during baking.
Traditionally the casserole is served hot from the oven and forms part of the Swedish julbord (Christmas buffet). It stands alongside pickled herring, meatballs and cured salmon, yet it’s so easy to assemble that many families enjoy it year‑round as a comforting lunch. In Finland the same dish appears on tables as Janssonin kiusaus, and home cooks make similar casseroles with smoked ham (known as kinkkukiusaus) or even salmon.
Who was Jansson? The Story Behind the Name
Although the casserole’s flavour is unmistakable, its name is surprisingly controversial. One popular theory links it to Pelle Janzon, an opera singer and gourmand who loved sprats and heavy food. Some sources, including Sweden’s official website, state that the dish was named after him. However, food historian Barbro Stigmark uncovered another story: her mother served a sprat‑and‑potato casserole at a 1920s dinner party and named it after the 1928 film Janssons frestelse to make the dish sound “modern and sophisticated”. The film, a Swedish comedy about a preacher named Jansson being tempted by sin, was a hit, and the name stuck. Adding to the confusion, Finnish sources also mention an 19th‑century preacher Erik Jansson, claiming that his hearty appetite inspired the name. Whatever its exact origin, the casserole wasn’t codified in print until the 1940s, when it quickly became a Swedish favourite.
Jansson’s Temptation – The Swedish Potato Gratin That’s Hard to Resist
Ingredients
Method
- Preheat your oven to 400°F (200°C).
- Lightly butter a 9×13-inch (about 23×33 cm) baking dish.
- Peel the potatoes and cut them into thin matchsticks, about ¼ inch (0.5 cm) thick.
- If you work slowly, you can keep them in a bowl of cold water to stop browning—but dry them very well in a clean kitchen towel before layering, or the gratin will be watery.
- In a large skillet, melt 3 tablespoons butter over medium heat.
- Add the sliced onions and a small pinch of salt.
- Cook 8–10 minutes, stirring now and then, until soft and sweet but not browned.
- Take off the heat and set aside.
- Open the cans of Swedish spiced sprats.
- Lift out the fillets and cut them into rough pieces or strips.
- Reserve 1–2 tablespoons of the brine from the can.
- In a pitcher or bowl, whisk together:2 cups heavy cream½ cup whole milk½ teaspoon pepperA small pinch of salt (you can adjust later)1–2 tablespoons sprat brine for that classic sweet-salty seasoning.
- Spread ⅓ of the potatoes in an even layer in the dish.
- Top with ½ of the onions and ½ of the sprat pieces.
- Add another ⅓ of the potatoes, then the remaining onions and sprats.
- Finish with the last ⅓ of the potatoes on top.
- Pour the cream mixture evenly over everything—press down gently with a spoon so the cream seeps in.
- Melt the remaining 2 tablespoons butter.
- Sprinkle the top with ½ cup breadcrumbs, then drizzle the melted butter over the crumbs.
- Bake at 400°F (200°C) for 20 minutes, then reduce the heat to 350°F (175°C) and continue baking for another 25–30 minutes, or until:The potatoes are completely tender when pierced with a knife.The top is deep golden and crisp, and the cream is bubbly around the edges.
- If the top browns too fast, you can tent loosely with foil for the last 10–15 minutes.
- Let the casserole rest 10–15 minutes before serving so it can set slightly.
- Serve warm with crispbread or rye bread, a simple green salad, and maybe pickled beets or quick pickled cucumbers on the side.
Notes
Condiments & Serving Suggestions
Swedes rarely eat Jansson’s Temptation alone. Traditionally it is served with crispbread (knäckebröd), aged Västerbotten cheese and a simple salad. Here are some tasty accompaniments:
- Pickled cucumber or beetroot. The sweet‑sour punch of pickled vegetables balances the rich creaminess.
- Fresh green or cabbage salad. A crunchy side salad adds freshness; a shredded cabbage salad or mixed greens dressed with a sharp vinaigrette works well.
- Swedish smörgåsbord staples. At Christmas the casserole nestles beside pickled herring, meatballs and gravlax on the julbord. Serve it alongside those classics for an authentic Nordic feast.
Modern Twists & Regional Variations
Jansson’s Temptation is one of those dishes that practically begs you to play with it. Once you understand the basic formula—potatoes, onion, creamy sauce and something savoury and salty—you can start exploring all kinds of “temptations”.
Vegetarian “Hansson’s frestelse”
A well-known vegetarian variation skips the fish entirely. Instead, it leans on deeply sautéed onions, mushrooms, capers and sometimes a touch of seaweed to bring back that savoury, briny character. The method is very similar to the original: thin potatoes and onions are layered in a dish, the “umami boosters” are tucked in between, and everything is baked in dairy or plant-based cream until the top turns golden and crisp. Many modern plant-based versions use oat cream or other non-dairy alternatives and still deliver that cosy, traditional casserole feeling.
Karlsson’s frestelse
In this hearty twist, the sprats are swapped for seasoned ground beef. The meat is browned together with onions, then layered with potatoes and cream just like the classic. The result is a richer, meatier casserole that still tastes unmistakably Scandinavian, and it has become a bit of a comfort-food favourite in some Swedish homes. Serve it hot with a spoonful of lingonberry jam and a crisp green salad to balance the richness
Mackerel Jansson’s
Another modern spin uses smoked mackerel instead of sprats. The smoked fish adds a deeper, almost bacon-like flavour that works beautifully with the sweet onions and cream. Some cooks par-boil the potatoes first so the whole dish bakes more quickly, and often serve it with quick pickled cucumber or radish on the side for freshness and crunch.
Matjessill twist
If you enjoy Nordic pickled herring, you’ll sometimes see Jansson’s Temptation made with matjessill—sweet-cured, spiced herring—in place of sprats. The casserole is assembled in the same way, but the flavour is slightly milder and sweeter, with a more pronounced pickled note.
Finnish “kiusaus” casseroles
Across the Baltic, Finland has happily adopted and adapted the idea. Janssonin kiusaus is essentially the Swedish dish translated into Finnish kitchens, while kinkkukiusaus (“ham temptation”) swaps the fish for smoked ham or leftover Christmas ham. You’ll also bump into versions starring salmon, sausage or extra cheese. The core stays the same: thin potatoes, onion, something salty and savoury, and a creamy bake that works just as well for a weekday lunch as it does on a holiday table.
Conclusion: A Temptation for Every Occasion
Jansson’s Temptation may have murky origins, but its appeal is clear. The combination of creamy potatoes, meltingly sweet onions and savoury spiced sprats makes it irresistible. By using genuine Swedish sprats and embracing the simplicity of this casserole, you can serve an authentic Nordic comfort food that works as a festive side dish or a quick weekday lunch. And with so many modern twists – from vegan versions with capers to mackerel‑packed makeovers – there’s a Jansson’s Temptation for everyone. So gather your ingredients, layer up those potatoes and let this Swedish classic tempt you.