1) For mignonette sauce, place the shallots, vinegar and sugar in a small saucepan and bring to a boil. Cook uncovered for 1 minute. Remove from the heat and allow to cool to room temperature. Add the pepper and herbs and serve with the raw oysters.
2) For the mustard sauce, combine all the ingredients and serve with the seafood
3) Fill a large platter with crushed ice. Place the seafood and lemons artfully on top of the ice. Serve with the sauces.