If you have already rady fillets, you can go to step two. If the fish is fresh, clean and wash the fish and remove th spine in a way the fillets keep together at the fish back. In the ready fillet one side is then the outer skin of the herring and if you turn it around, it is the inside.
Take the fillets and sprinkle salt, pepper and dill on the inner sides, then put the filets together insides against each other, so the skin sides are outside.
Beat the egg with the milk. Dip the double-fillets in the egg mixture and then slightly in the flour.
Fry the fillets on both sides with some oil or butter.