Season the flour with salt and pepper. Dip each well-drained oyster in the flour, egg and breadcrumbs, pressing the breadcrumbs on with your fingertips to secure.
Heat the oil in a deep-fryer or a deep saucepan to 190 degrees C or until the oil is hot enough that a cube of stale bread dropped in turns golden in 20–30 seconds.
Deep-fry six oysters at a time in the frying basket for 2–3 minutes or until crisp and golden, turning them once during cooking. Drain on crumpled paper towels.
Sprinkle with sea salt and ground black pepper. Serve on the shell, if desired, with wedges of lemon.