Fiskegrateng

Ingredients

• 1⅛ lbcod filletskinless and boneless, cut into pieces; other white fish or cooked leftovers also work
• 1¾ ozbutterfor the roux and greasing the dish
• 4 tbspflourfor the roux
• 1⅔ cupsmilkfor the white sauce
• 4eggwhole or separated, whites then beaten stiff
• 3½ ozmacaroniuncooked weight, boiled beforehand; leftover cooked pasta also works
• 2¾ ozcheesegrated, e.g. Norwegian white cheese, Gouda or Parmesan; for topping or in the sauce
• 4 tbspbreadcrumbsfor the topping
• 1 tspsalt
• ½ tsppepperwhite or black, ground
• ½ tspnutmegfreshly grated
• 1leekwhite part only, thinly sliced (optional)
• 1 clovesgarlicfinely chopped or crushed (optional)
• potatoesboiled or mashed, for serving (optional)

Method

1. Prepare the oven and macaroniHeat the oven to 355 °F and grease an ovenproof dish with a little of the butter. Cook the macaroni according to the packet instructions and drain.
2. Prepare the fishCut the cod fillet into bite-sized pieces. Either use the pieces raw, or poach them briefly in hot salted water that is no longer boiling, then drain.
3. Start the rouxMelt the remaining butter in a saucepan. If you like, soften the white part of the leek and the garlic in it first for a few minutes until translucent. Then stir in the flour and cook it briefly without letting it colour.
4. Cook the white sauceAdd the milk a little at a time, stirring constantly so no lumps form. Bring the sauce to the boil and let it simmer gently for 2–3 minutes until it thickens.
5. Season and add the eggsTake the sauce off the heat, let it cool slightly and season with salt, pepper and freshly grated nutmeg. Stir in the eggs one at a time. For a lighter gratin, separate the eggs, stir in only the yolks and whisk the whites until stiff.
6. Fold in fish and pastaGently fold the macaroni and the fish into the sauce. If you separated the eggs, fold in the beaten whites last, keeping the mixture airy.
7. Fill the dish and topSpoon the mixture into the prepared dish and scatter the grated cheese and the breadcrumbs evenly over the top.
8. Bake and serveBake for 30–45 minutes, until the top is golden brown. Let it rest briefly, then serve with potatoes and vegetables or a raw vegetable salad.

Tips and variations

Fiskegrateng also works without macaroni, with just fish baked in the egg and flour sauce. Cooked fish left over from the day before can take the place of the raw cod; the gratin then needs a shorter time in the oven. Salted or smoked fish works as well; season the sauce with less salt, and if the fish is already cooked, shorten the baking time here too. For a more robust flavour, add softened shallots, garlic, a pinch of cayenne, Parmesan and fresh herbs such as parsley and chives. Without pasta or flour, lay the fish on a bed of gently cooked leek, pour over eggs beaten with milk, dill and lemon juice, scatter with Gouda and bake at 200 °C. Serve the gratin straight from the dish, with boiled potatoes or mash.