1. Take 1 sheet of plastic film and in center, put 1/4 shredded potato and spread out everywhere.
2. Place 1 shucked oyster in center of potato, picking up each corner of film carefully. Bring to center, creating an egg shape mold. Twist film to hold shape and freeze. (can be done ahead)
Heat 4 Cups vegetable oil to 375° in small pot so oil is deep level. Remove frozen potato and oyster from film and fry in oil until golden brown. Ladle potato leek soup in bowl. Top with Crème fraiche, long chive and caviar. Arrange pieces of leek around bowl and top with caviar. Serve.