Thinly slice the spring onions.
In a bowl lightly whisk the eggs with a couple pinches of salt, then add the spring onion.
Cut off and discard the woody ends of the asparagus, then spray them with oil and lightly grill them in a griddle pan. They should remain crispy.
Heat a frying pan then add half of the oil, then half of the egg mixture. Let the mixture spread out evenly, creating a large circle. Turn the heat down, then sprinkle some grated cheese and parsley on top.
When the surface of the omelette is no longer runny, put half of the asparagus on one side of the omelette, then, using a spatula, fold the other half over the asparagus. Press down lightly.
After a minute or so, transfer it to a plate and scatter some more cheese on top.
Make another omelette with the remaining egg mixture and asparagus.
Cut the omelette in half, then serve.