This recipe is from cookitsimply.com.  Serves 4.

4 fresh herrings

1 tablespoon oil

1 tablespoon white wine vinegar

Salt and pepper

4 spring onions, chopped

1/2 pint sour cream

1 teaspoon mustard powder

Cayenne pepper

1 tablespoon chopped fresh dill

Garnish:

Additional cayenne pepper

Halved lemon slices

Additional chopped fresh dill, plus a few sprigs
 

1. Wash the insides and outsides of the fish and pat dry. Cut slits down both sides of each fish. Brush the fish with oil, then spoon the vinegar into the slits and season the fish generously.

2. Heat the grill to medium heat and grill the herrings on one side for 6 minutes. Turn the fish over, brush with a little more oil and cook for a further 6 minutes. Transfer the herrings to a serving plate and keep warm.

3. Mix the remaining ingredients together to make the sauce, pour it into a serving bowl, garnish, and serve alongside the herring.