Ukrainian Savory Herring Spread - cooking recipe

Ingredients

1 fat salt herring fillet
2 hard-boiled eggs
1 small onion, grated
2 tablespoons soft butter
pepper
1 teaspoon prepared mustard
1 tablespoon vinegar

Preparation

Wash and clean the herring, discard the head, and soak in cold water 1 to 2 hours. The herring should retain some saltiness.
Remove the skin and bones. Rinse the fillets and pat dry.
Grind the fillets or chop them very finely.
Press the eggs through a sieve, reserving 1 egg yolk for a garnish.
Combine the chopped herring with the sieved eggs and the remaining ingredients.
Mash to a smooth paste. If the mixture is very soft, chill it before spreading. Garnish with the sieved egg yolk and finely chopped parsley or scallions.