Brush the sandwich toaster with a little sunflower oil and preheat to its highest setting.
In a bowl, combine the fish, cheese, cream, seasoning, and egg. Brush one side of each side of bread with oil.
Place one slice of bread in the toaster (oiled side down). Carefully press the bread into the recesses with the back of a spoon, taking care not to tear the bread, or the filling will leak out. Carefully spoon the filling into the recesses of the sandwich toaster and place the second slice of bread on top (oiled side up).
Close the lid of the sandwich toaster until it rests gently on top of the sandwich (do not close the lid fully or lock it at this stage). Leave the sandwich to cook like this for 3 minutes, then slowly close the lid, lock it shut, and cook for a further 3 minutes until crisp and golden.