Wash spinach well and drain. While still a little wet, cook in a saucepan over moderate heat until wilted. Drain and when cool enough to handle, squeeze out excess water and roughly chop. Mix with eggs, parmesan, spring onions and salt. Heat a few teaspoons of oil in a large frying pan. Spoon in some of the mixture and cook over a moderate heat until coloured, then gently flip over and cook until the fritter is just set.