Stegte Sild med Bløde Løg og Kogte Kartofler

Ingredients

Equipment Needed

• •Heavy frying pan, large enough for 4 fillets without crowding
• •Heavy-bottomed saucepan for the løgsovs
• •Large pot for the potatoes
• •Whisk

Instructions

1. 1

   Start the onions

   Melt the 50g butter for the løgsovs in a heavy-bottomed saucepan over a low heat. Add the sliced onions, a generous pinch of salt, and the teaspoon of sugar. Stir everything through the butter, then put the lid on and let the onions cook very gently for twenty to twenty-five minutes, stirring every five minutes or so. You want them completely soft, sweet, and translucent, collapsing into each other. The sugar helps them along, but the real work is done by patience and low heat. If they take on color, your heat is too high. Bløde løg means soft onions, and soft is what you're after.

   Start the onions first. They take the longest and they cannot be rushed. Everything else fits around them.
2. 2

   Boil the potatoes

   While the onions soften, put the potatoes into a large pot of cold water with a generous handful of coarse sea salt. Starting in cold water lets the heat travel evenly from the outside in, so the centers cook through without the outsides going mealy. Bring to a steady simmer and cook until a thin knife slides into the center with no resistance at all, about twenty minutes depending on size. Drain them and put the lid back on slightly ajar. The residual heat dries their surfaces, which matters when the butter and sauce meet them on the plate.

3. 3

   Build the løgsovs

   When the onions are completely soft, sprinkle the two tablespoons of wheat flour over them and stir it in. Cook for two minutes, stirring constantly. The flour needs this time to lose its raw taste, and you'll notice the mixture thicken and start to pull away from the sides of the pan slightly. Now pour in the milk in a slow, steady stream, stirring as you go. Add the bay leaf and the nutmeg. Bring the sauce to a gentle simmer and let it cook for eight to ten minutes, stirring regularly, until it has thickened to the consistency of double cream. It should coat the back of a spoon and hold a line when you draw your finger through it. Season with salt and white pepper. Remove the bay leaf. The sauce should taste of butter and slow-cooked onion, rich and sweet and mild.

   If the sauce gets lumpy, don't panic. A whisk and thirty seconds of vigorous stirring will smooth it out. Lumps are just flour that hasn't dissolved yet.
4. 4

   Dredge the herring

   Pat the herring fillets completely dry with kitchen paper. This is not optional. Wet fish steams instead of crisping, and the rugmel turns to paste instead of a crust. Season both sides with fine salt and pepper. Spread the rugmel on a plate and press each fillet into it, coating both sides, then shake off any excess. Dredge just before frying, not before. Rye flour absorbs moisture quickly and goes soft if it sits. The timing is part of the technique.

   Dark stone-ground rugmel gives the crust its nutty, slightly bitter edge and its deep brown color. Wheat flour would crisp too, but it tastes of nothing and the color is pale and generic. The rye is the Danish fingerprint on this dish.
5. 5

   Fry the herring

   Heat the 40g butter and the tablespoon of oil together in a heavy frying pan over medium-high heat. Butter alone burns before the fish is done. Oil alone gives no flavor. Together they give you a golden crust and the nutty richness that makes these taste right. When the butter foams, the foam subsides, and it smells of hazelnuts, lay the fillets in skin-side down. Don't crowd the pan. Work in two batches if you need to. Cook for two to three minutes without moving them. The rye crust should go deep golden brown and the edges should curl slightly. Flip and cook for one minute more on the flesh side. The fillets are thin. They don't need long.

   Listen to the pan. A steady, confident sizzle means the temperature is right. If it goes quiet, the heat has dropped and the fish is absorbing fat instead of crisping. If it screams, pull the pan off the heat for a moment.
6. 6

   Plate and serve

   Place the warm potatoes on one side of each plate and the fried herring fillets alongside. Spoon the løgsovs generously over the herring, letting it pool around the potatoes too. The sauce is the bridge between everything on the plate. Add pickled beetroot to the side and finish with several fronds of fresh dill over the fish and the sauce. Serve immediately. This is a dish that waits for nobody. The herring should be crisp, the sauce should be warm, the potatoes should steam when you cut them open. That's the moment. Tak for mad.

Chef Tips

• •Use dark stone-ground rugmel for dredging, not light rye and not wheat. The coarse grind and the deep color are what give the crust its character. If you can't find rugmel, a Scandinavian grocery or online supplier will have it. It keeps for months in a sealed jar.
• •The løgsovs should be rich but pourable, not stiff. If it thickens too much as it sits, stir in a splash of warm milk to loosen it. The consistency you want is closer to double cream than to paste.
• •Fresh herring is best. Ask your fishmonger to fillet and pin-bone them. If you're using frozen fillets, thaw them slowly in the fridge overnight and pat them very dry before dredging. The crust depends entirely on the surface being dry when it hits the flour.
• •Pickled beetroot from a jar is perfectly fine here. This is mormormad, not restaurant food. The sweet-sharp vinegar of the beets is what balances the butter and cream in everything else on the plate.

Advance Preparation

• •The løgsovs can be made several hours ahead and reheated gently with a splash of milk. It thickens as it cools, so loosen it before serving.
• •The potatoes can be boiled ahead and reheated in the warm sauce or in their own steam. The herring must be fried just before serving. Crisp rye crust does not wait.

Frequently Asked Questions

Nutrition Information

1 serving (about 600g)