Open the oysters and reserve bottom shells. Melt the butter in a saucepan. Add the wine, oysters, oyster juice, shallots, salt and pepper. Boil for 2 minutes. Strain. Reserve the oysters. Reduce the cooking liquid by half.
Add one half of the cream, and continue cooking to thicken the liquid. Cut the leeks into julienne. Blanch and cook in the remaining cream. Place an oyster in each shell. Spoon some of the leek mixture over each oyster. Top with the reduced sauce . Spoon caviar over each oyster just before serving.