I found this recipe, which confirms Sarah's suggestion.

Hake in green sauce
Ingredients: 4 thick slices of hake
250 grams of clams
125 ml of fish broth
2 tablespoons white wine
4 cloves of garlic
Chopped parsley
Flour
Olive oil
Salt
Preparation:
Soak the clams in salty water for an hour to allow them to eject any remaining sand. Peel and finely chop the garlic. Place the oil in a saucepan and heat. Add the garlic and brown slightly. Stir in a spoonful of flour and leave for half a minute.

Add the wine and fish broth and heat up. Add the chopped parsley and the hake. Cook for three minutes after each step, shaking the saucepan gently. Add the clams and continue to shake the saucepan until the sauce thickens.

Your dish will be ready in a few minutes. You won't believe how good it is.