How to make
In a bowl, beat the olive oil and freshly squeezed lemon juice from 1 lemon. Divide the resulting mixture into two halves and marinate the fish fillets in one for about 40 minutes.
While the fish is marinating, boil or steam the potatoes in salted water. Peel them, mash them with a fork and add the milk and butter. Add as much salt as you like and puree, until a smooth mixture is obtained.
Finely chop the green spices and roll the fish fillets in them, so that they aquire a thick green shell. Grill them on a well heated grill on both sides. Serve the hake top of the mashed potatoes and pour the leftover sauce over them.