Must try in Sweden

Janssons Frestelse.

Name: Janssons Frestelse (Swedish Potato and Sprat Gratin)
Prep time: 30 min
Cook time: 55 min
Total time: 1 h 35 min
Yield: 6 servings
Cuisine: Sweden
Ingredients: 1 kg floury potatoes, peeled and cut into 5 mm matchsticks; 3 medium yellow onions, halved and thinly sliced; 50 g butter; 250 g Swedish ansjovis (spice-cured sprats), 2 tins, drained but brine reserved; 3 tbsp brine from the ansjovis tins; 400 ml double cream; 100 ml whole milk; 3 tbsp dry breadcrumbs, for the top; ½ tsp ground white pepper; to taste salt — taste before adding, the sprats are salty

Swedish Potato and Sprat Gratin

Janssons frestelse · say it: YAHN-suns FRES-tel-seh

Janssons frestelse is a potato gratin with a secret weapon: Swedish ansjovis, small sprats cured in a sweet spiced brine of allspice, clove, cinnamon and sandalwood. Chopped fine and scattered between layers of matchstick potato and softened onion, they dissolve almost completely during baking, leaving no fishiness — just a deep, sweet-savoury saltiness that people who swear they hate anchovies cannot identify and cannot stop eating. The cream reduces into the potato, the surface goes bronze and slightly crisp, and the whole thing tastes far more complicated than its four main ingredients suggest. On a Swedish julbord it is the only hot dish, and it disappears fastest.

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Swedish Potato and Sprat Gratin

Gate: Sweden
Prep: 30 min
Cook: 55 min
Total time: 1 hr 35 min incl. 10 min rest
Serves: 6
Status: Medium
Nutrition / serving · estimated: Calories 470 kcal; Protein 15 g; Carbs 34 g; Fat 31 g; Fiber 4 g; Sodium 1100 mg

Why this recipe works.

Cutting the potatoes by hand into real matchsticks — not slices — is what lets the cream reduce into every layer.
The onions are sweated slowly first, so they melt into the gratin instead of staying raw and sharp in the middle.
Explains exactly what Swedish ansjovis is and how to adapt if you can only find Mediterranean anchovies.
Cream is added in two stages, so the top layer browns properly instead of poaching under liquid.

Tips from our kitchen.

Do not rinse the cut potatoes. The surface starch is what thickens the cream into a sauce; wash it off and you get a watery gratin.
Use the brine from the tin. Two or three tablespoons of that spiced liquid carry more of the dish's character than the fillets do.
Cut the potatoes about 5 mm thick and no thicker. A mandoline with a julienne blade is quicker, but a knife and patience give better texture.
Add the second half of the cream only after 20 minutes of baking, so the top gets a head start on browning.
Let the gratin stand 10 minutes out of the oven. Straight from the heat the cream is still loose; it sets to the right consistency as it cools slightly.
Season with salt only at the very end, and taste first — the sprats and their brine are already salty enough for many palates.

Substitutions.

Swedish ansjovis (spice-cured sprats) → 8–10 Mediterranean anchovy fillets in oil, plus ¼ tsp ground allspice, a pinch of ground cloves and 1 tsp sugar: Use roughly half the quantity you would of ansjovis — Mediterranean anchovies are far saltier and taste of the sea rather than of spice. Nordic and IKEA food shops sell real ansjovis in tins.
Matjes herring → A perfectly acceptable Swedish alternative to sprats: Some families make Janssons with matjes fillets instead. It is a slightly softer, sweeter result and is not considered heresy.
Double cream → Half cream, half whole milk: Lighter and still works, but reduce more slowly and give it an extra 10 minutes — thinner liquid takes longer to thicken around the potato.

Variations.

Vegetarian Janssons: Replace the sprats with finely chopped pickled beetroot and a spoonful of capers plus a pinch of allspice and sugar. Not traditional, but it reproduces the sweet-salt-spice profile that makes the dish work.
Individual gratins: Baked in small ramekins for a starter, cutting the oven time to about 35 minutes. Each one gets its own browned crust, which is the best part.
Party leftovers version: Reheated in a hot pan with a little butter until the bottom catches and crisps, then topped with a fried egg — the unofficial Swedish morning-after breakfast.

Storage & reheating.

Refrigerate for up to 3 days, covered. Reheat at 175°C for 20–25 minutes rather than in a microwave, which turns the potato waxy and splits the cream. Janssons does not freeze well: the potato goes grainy and the cream separates on thawing, and no amount of stirring recovers it. You can, however, assemble the whole gratin up to a day ahead, hold it in the fridge without the cream, and pour the cream on just before baking — add 10 minutes to the oven time if it goes in cold.

Serve with

A cold beer, dark rye bread, and the rest of a Christmas smörgåsbord — or a green salad if it is the whole meal.

The story behind Janssons Frestelse.

The name means "Jansson's temptation", and nobody can prove who Jansson was. The tidiest theory, and the one most often printed in Sweden, points to the opera singer Pelle Janzon, a well-known gourmand of the late nineteenth and early twentieth century. Another traces the name to a 1928 Swedish film called Janssons frestelse. A third, more mischievous version attaches the dish to Erik Jansson, a nineteenth-century religious leader who preached asceticism and was supposedly caught eating something delicious in secret. None of these is documented well enough to settle the question, and Swedes generally enjoy the ambiguity rather than resolving it. The recipe itself appears in print in Sweden in the 1940s and spread quickly.

What is not ambiguous is the fish. Swedish ansjovis is not the Mediterranean anchovy. It is sprat — skarpsill — cured in a sweet, heavily spiced brine, and it is sold in flat tins whose liquid is as important as the fillets. Substituting salt-packed Mediterranean anchovies produces a dish that is aggressively salty and tastes of the sea rather than of Christmas spice, which is why so many non-Swedish attempts at Janssons come out wrong and get blamed on the recipe. If you use anchovies, use fewer of them and add a pinch of allspice and sugar to approximate the brine, and know that you are making a cousin rather than the thing itself.

On the julbord, Sweden's enormous Christmas buffet, Janssons occupies a specific slot: after the cold rounds of pickled herring, cured salmon and cold cuts, when people want something hot. It also has a well-earned second life as late-night food after a party, eaten standing at the counter straight from the dish, which is arguably how it tastes best.

Questions, answered.

Does Janssons frestelse taste fishy?

No, and this surprises almost everyone. The sprats break down completely during the long bake and leave behind a sweet, savoury saltiness rather than any recognisable fish flavour. People who dislike anchovies routinely eat several helpings without identifying what is in it.

Can I use regular anchovies instead of Swedish ansjovis?

You can, but halve the quantity and adjust. Swedish ansjovis are sprats cured in a sweet brine spiced with allspice, cloves and cinnamon, while Mediterranean anchovies are simply salt-cured and much stronger. Adding a quarter teaspoon of ground allspice, a pinch of cloves and a teaspoon of sugar gets you closer to the original profile.

Why is my gratin watery?

Two common causes. Rinsing the cut potatoes washes away the surface starch that thickens the cream, so never rinse them. The other is using waxy salad potatoes, which hold their water instead of releasing starch — choose a floury or all-purpose variety like King Edward, Maris Piper or Russet.

Should the potatoes be sliced or cut into sticks?

Cut into matchsticks, roughly 5 mm square and 5 cm long. Sticks give the cream far more surface to cling to and cook through evenly, which is what separates Janssons from an ordinary sliced potato gratin. Slicing works in a pinch but produces a denser, heavier dish.

Who was Jansson?

Nobody knows for certain. Candidates include the opera singer Pelle Janzon, a 1928 Swedish film of the same title, and a nineteenth-century preacher supposedly caught indulging in secret. None of these is properly documented, and the uncertainty is now part of the dish's folklore in Sweden.

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