500 g of cleaned Baltic herring
2 onions (peeled and cut into semi-circles)
300 ml of crushed tomatoes or tomato purée
100 ml of olive oil
1 tbsp of sugar
1 tsp of salt
Cayenne pepper (if desired)
2 bay leaves
Place the fish and onion alternately in an oven dish.
Mix together the crushed tomatoes, sugar, oil, salt, black pepper and (if desired) Cayenne pepper. If you are using garlic, also add it to the sauce.
Pour over the fish. Stick a few bay leaves into the sauce. Bake in a pre-heated oven at 180-200 °C for around 15 mins. Remove the oven dish, allow to cool and, if desired, place the fish in a jar. Store in a cool place.