Chop the onion and add to a large saute pan with the olive oil. Cook on a medium heat for 2 minutes, then add the chopped asparagus (you want it cut to pieces about an inch long).

Add the frozen peas and cook over the medium heat until they have warmed through - this should only take about 5 minutes.

Crack the eggs into a large bowl, add the parsley and some salt and pepper and beat until well combined.

Pour the egg mixture evenly over the veg in the pan, making sure it covers all of the vegetables, and move around quickly with a wooden spoon to ensure it fills any gaps. Cook over a low-medium heat (do not stir - or you get scrambled egg!) for 5-7 minutes until the egg has mostly set.

Crumble the feta evenly over the top and pop under a high grill until the egg is completely set and the top is golden brown (about 10 minutes).