Crack the eggs whites into a bowl, season with salt and pepper and beat the mixture with a fork or whisk.
Add the egg mixture to a non-stick pan and as it begins to cook, add the baby spinach.
Slide a spatula under one side of the omelette and fold over in half to create a semi-circle.
Let the folded omelette cook for a further minute (less if you like the centre soft or more if you like it cooked through), then slide it out of the pan and onto a plate. Garnish with spring onion and serve and eat immediately.
