Jansson's Temptation

Ingredients

• •2 lb waxy potatoes, peeled and cut into thin matchsticks
• •2 onions, thinly sliced
• •2 tins Swedish anchovies/sprats (ansjovis), with brine
• •1 cup crème fraîche
• •1/2 cup heavy cream
• •2 tbsp butter, plus more for greasing
• •1/2 cup breadcrumbs
• •Salt and white pepper, to taste

Steps

1. 1.Butter a baking dish, then layer one-third of the potato matchsticks over the base and scatter half the sliced onions and half the anchovies, chopped in half, on top.
2. 2.Cover with half the remaining potatoes, then scatter the rest of the onions and anchovies, and finish with a final layer of potatoes on top.
3. 3.Heat the crème fraîche and cream together gently with a little of the anchovy brine, salt, and white pepper until just starting to simmer.
4. 4.Pour this warm cream mixture evenly over the potatoes.
5. 5.Sprinkle the breadcrumbs over the top and dot with butter.
6. 6.Bake at 400F (200C) for 1 hour, then cover loosely with foil and bake for another 30 minutes until the potatoes are completely tender and the top is golden.
7. 7.Let rest for 10 minutes before serving - the anchovies here are Swedish-style sprats cured in a sweet, spiced brine, milder and less fishy than Mediterranean anchovies, which is what keeps the finished gratin surprisingly delicate rather than overpoweringly fishy.