If you've only ever had oysters on the half shell, meaning in their raw state, this dish will be a real revelation. You must start off by cleaning the oysters very well, and then of course opening them, but be sure to save the "liquor" inside. Keeping the oysters in their bottom shells, a piquant sauce is poured over each and then they are sprinkled with grated parmesan and baked until what you have is perfection.