I loved the flavor of the sauce, but I am wondering whether by "mash" what is really meant is smashing together in mortar and pestle? The sauce was very rough - big pieces of parsley and the garlic probably would have been almost whole except that I had minced it. So I took my stick blender to it. The sauce was not totally smooth as it would be in a blender or food processor but it was much more appealing than it was originally. Incidentally, I made only two servings of fish, but all of the sauce. I have no sauce left - perhaps I was too generous, but it was tasty. The bit I had left I spooned onto a hot potato. So if you like your fish saucy, you might want to allow for a bit more sauce. Oh, and I peeled my potato, because I really don't care for potato peel in finished dishes.