Take some anchovy paste--one tablespoon, two tablespoons of
chopped
parsley, some capers and chopped pickles, one teaspoon of French
mustard and the yolks of two hard-boiled eggs. Work this all together
into a paste, then add three tablespoons of olive-oil and two or three
of vinegar and a pinch of salt and pepper. This sauce is good with
both meat and fish.
Source:
Simple Italian Cookery