Preheat oven to 160 C / Gas mark 3. Lightly grease a 23cm pie or quiche dish.
Place spinach in a small saucepan. Wilt over medium heat, stirring occasionally until soft then drain off any remaining liquid. Stir in spring onions, eggs and grated cheese. Pour mixture into prepared dish.
Bake uncovered in preheated oven for 45 to 60 minutes, until eggs are set.