Pan-Fried Herring in Pickling Liquor (Scandinavian)

The herring in this recipe from chef Magnus Nilsson of Fäviken are "floundered", a traditional Scandinavian preparation in which the herring sides are removed from the carcass but left attached by the skin over the backbone, forming one large fillet. Ask your fish monger to do this for you, or buy individual fillets and tie two together with kitchen twine for each "floundered" fillet. Allow at least 12 hours for pickling.

8 whole herring, small trout or bluefish, floundered
sea salt
white pepper, freshly ground
1⁄3 cup Dijon mustard
2 Tbsp. fresh dill, minced
2 Tbsp. fresh flat-leaf parsley, minced
8 Tbsp. butter
2 cups sugar
2½ cups distilled white vinegar
1 medium red onion, thinly sliced crosswise
1 large carrot, thinly sliced crosswise
10 whole allspice berries
10 whole black peppercorns
5 whole white peppercorns
2 bay leaves

To Serve:
boiled potatoes
rye toast

Place the herring on a work surface and open each like a book so the flesh is facing up. Season the flesh side of the fillets with salt and white pepper, and then brush each with the mustard. Sprinkle the fillets with the dill and parsley, and then close each like a book, so the flesh sides are touching.

In a large nonstick skillet, heat the butter over medium. Working in batches, add the fillets and cook, turning once, until the skin sides are lightly browned, 2-3 minutes. Transfer the fillets to paper towels to drain, and then arrange them in a baking dish large enough to fit them in a single layer.

Meanwhile, in a medium saucepan, bring the sugar and 1½ cups water to a boil, stirring to dissolve the sugar. Remove the pan from the heat and stir in the vinegar, onion, carrot, allspice, black and white peppercorns, and bay leaves. Gently pour the pickling liquid and aromatics over the fillets and let cool to room temperature.

Cover the dish with plastic wrap and refrigerate for at least 12 hours. To serve, drain the fillets and serve with some of the pickling liquid and aromatics alongside boiled potatoes and rye toast.

Makes 8-10 servings.