Parsleyed Cod with Mustard Butter Sauce

Parsley has been associated with fish since the Middle Ages, one of the principal herbs used in the famous green sauce. I have changed this classic cod and parsley combination to give a purée of parsley mixed with spinach, which is spread over the fish, so that the parsley flavour comes through in every bite. If you serve this with some curly kale, roast potatoes and a mustard butter sauce, you will have a complete meal.

If pig’s caul is unavailabl