Snabb Janssons Frestelse
(snab YAHN-sohns FREHS-tell-seh)
Mormors Arv (Heritage, Midsummer, and Julbord)
A Tuesday-night Jansson's doesn't wait around for you to spend hours peeling and julienning potatoes into perfect matchsticks. But modern Swedes know a secret: high-quality frozen shoestring fries. Tossing them into a 9x13 glass baking dish with a pint of heavy cream yields a beautifully crispy gratin on a random weeknight, provided you follow the only inflexible rule—you need the spiced brine of Swedish sprats, not supermarket tinned anchovies. Bake in a 400-degree oven until the foil crackles.
Ingredients
- yellow onions2 large
- unsalted butter3 tbsp
- frozen shoestring French fries1 1/2 lb
- Swedish spice-cured sprats4 1/2 oz
- heavy whipping cream1 1/2 cup
- whole milk1/4 cup
- fine dry breadcrumbs3 tbsp
- black pepper1 tsp
Method
- 01
Preheat the oven to 400°F and generously butter an 8x8-inch baking dish.
- 02
Slowly sauté the sliced onions in one tablespoon of butter over medium-low heat until incredibly soft and sweet.
Do not let them brown; you want them entirely translucent to provide a sweet baseline against the salty fish.
- 03
Whisk the reserved sprat brine into the heavy cream and whole milk.
This step is non-negotiable. The spiced brine from the tin, laced with cinnamon and allspice, is the literal liquid gold that gives the dish its authentic flavor.
- 04
Build the gratin in alternating layers of potatoes, onions, and sprats.
Start with a third of the potatoes, half the onions, and half the chopped sprats in the buttered dish. Repeat, then finish with a final layer of potatoes to ensure the fish is completely covered, finishing with a generous grind of black pepper over the top.
- 05
Slowly pour the cream and brine mixture evenly over the entire dish.
The liquid should come up to just below the top layer of potatoes.
- 06
Sprinkle the breadcrumbs across the top layer and dot with the remaining butter.
Cut the remaining two tablespoons of butter into tiny cubes so it melts evenly over the breadcrumbs.
- 07
Bake for 40 to 45 minutes until the cream is bubbling and the top is a deep golden brown.
If the top is browning too rapidly, loosely tent the dish with aluminum foil for the final fifteen minutes.
- 08
Let the casserole rest for at least ten minutes before serving.
The cream needs time to settle and bind with the potato starches, yielding a beautifully cohesive gratin. Serve warm.
Notes
Never use standard Mediterranean anchovies from the pizza aisle.
They will make the dish aggressively salty and fishy. Look for pink tins of 'Abba Grebbestads Ansjovis' or 'Skarpsill' at IKEA. If you are desperate, finely chop lightly rinsed pickled Matjes herring as a substitute, or use half a tin of regular anchovies and whisk a half-teaspoon of allspice, a pinch of cloves, cinnamon, and a teaspoon of sugar into the cream.