Place the flour, egg and couscous into separate bowls. Stir the cumin and lemon zest into the couscous.
Now coat each oyster in flour, then dip them into the egg and lastly coat them in the scented couscous, chill them until you are ready to fry.
Heat the oil in a small pan to 180°C or until a cube of bread browns in less than thirty seconds.
Fry the oysters in the oil until crisp and golden brown. Do not over crowd the pot or over cook the oysters, they must be nice and succulent.
For the mayonnaise mix all the ingredients together and season to taste with salt and freshly ground black pepper. Arrange the rock salt onto a platter, place the empty shells onto the salt. Place a parsley leaf into the base of each shell, and top with a crumbed oyster. Serve with the chunky mayonnaise.