Marinated Herring with Red Onions
Soak herring in water in the refrigerator for at least 12 hours, then rinse thoroughly and remove any adhering scales if necessary. Cut off the heads, fillet the fish and remove the backbones. Rinse the fillets again thoroughly and drain. Cut the fillets lengthwise and roll tightly.
Rinse the lemons in hot water, wipe dry and cut into thin slices. Rinse chile pepper, trim, remove seeds and cut into rings. Bring the vinegar to a boil with 200 ml (approximately 3/4 cup) of water, lemon slices, sugar, salt and pepper to taste. Cover and simmer for about 20 minutes.
Peel the onions and cut into 3 mm (approximately 1/8-inch) thick slices. Layer herring rolls with onions in jars. Drain the vinegar mixture through a sieve and allow to cool to lukewarm. Pour the broth over the herring rolls, close the jars and let marinate for 2 days in refrigerator before serving.