Shuck all the oysters and remove from the shell. Do not discard the shell. Slice the leeks and wash them very well. In a small saute pan sweat leeks until tender and keep them warm.
Slice all the peppers very thinly in small strips, cook them with olive oil until tender and add the sherry vinegar. Place the leeks in the bottom of the shell. Sear the oysters quickly in a very hot pan and put them on top of the leeks. Spoon the peppers on top of each oyster and serve.