How to make
Eviscerate, then remove the head, fins and tail of the mackerel, wash, salt and sprinkle them with black pepper, lemon juice, oil and put them in a pyrex glass dish.
Chop the onion and leeks and pour them over the fish, add crushed dill, the remaining lemon juice, 2 tablespoons of oil and 2/5 cup (100 ml) of water with a little salt.
Bake for about 30 minutes in a hot oven with the lid on. When serving the hot fish, add 1 small chunk of butter.