9oz (250g)sprats(Swedish anchovies), or matjes herring
1 ¼cups (300ml)heavy cream
2tablespoons (30g)unsalted butter, cut into pieces
3tablespoonsbreadcrumbs or panko
Instructions
Preheat an oven to 450 °F (225°C).
Remove the sprats from the tin, reserving the liquid. Mix this liquid with the heavy cream.
Grease a large baking dish. Place a layer of the onions on the bottom. Follow with a layer of the sprats. Finish with a layer of the potatoes. Pour the cream and sprat liquid mixture over the top. Sprinkle with breadcrumbs or panko. Finally, arrange the butter pieces on top.