Fried Herrings & Onion Sauce

A traditional Danish way to serve herring: boned, breaded in a flour-egg-breadcrumb coating, and fried in generous butter until crisp. The creamy onion sauce on the side is a simple béchamel thickened with flour and butter, loaded with finely chopped onions and seasoned with a pinch of sugar to balance their sharpness.

Bone the herrings before breading. Run a sharp knife along both sides of the backbone, lift it out, and check for pin bones with your fingertips. Breading hides bones, so be thorough.

The three-stage breading (flour, then beaten egg, then breadcrumbs) gives a coating that stays put during frying. Each layer grips the next, building a shell that crisps evenly in the butter.

Kitchen Tips

• Fry in plenty of butter over medium heat. Butter browns and adds flavor, but burns fast over high heat. If the butter starts to darken too quickly, lower the flame.
• The onion sauce should be smooth before the onions go in. Stir the flour into the melted butter first, cook it briefly, then add milk gradually while whisking to prevent lumps.
• A pinch of sugar in the sauce is traditional, not sweet. It takes the raw edge off the onions and rounds out the flavor.
• Serve with boiled potatoes. Plain, starchy potatoes soak up the onion sauce and balance the richness of the fried fish.

Variations

• Pre-boil the onions in a little water before adding to the sauce for a milder, sweeter flavor.
• Add a teaspoon of whole grain mustard to the finished sauce for a tangy Scandinavian twist.
• Substitute mackerel fillets for the herring. Same oily fish family, similar cooking time.