There's nothing plain about these oysters or the sauces they are served with, though you need not do anything to the mollusks themselves except to pry them open, and there's a special knife to help you in that endeavor. The sauces are key, and it's worth making all three for a variety, and to please all palates. One tastes of apple and cider vinegar, another of strawberries and balsamic, and the last of shallot and red wine vinegar (this is known as a mignonette).