Cook the watercress, spinach and rocket in a small amount of water for 2 minutes, until the leaves wilt. Drain thoroughly, squeezing out the excess moisture. Puree with a hand-held stick blender, or chop very finely.
Whisk the Two Chicks egg white with a hand whisk for 3-4 minutes until light and frothy. Whisk in the chopped watercress mixture. Season with pepper.
Preheat the grill – meanwhile, heat a non-stick frying pan and spray with cooking spray or brush with vegetable oil.
Add the egg white mixture and cook over a medium heat until the base has set, then transfer to the grill to set the surface. The omelette should be done in 2-3 minutes.
Transfer the omelette to a warm serving plate and top with the cream cheese and the roasted peppers. Serve at once.
Cook's tip: Once opened, a carton of Two Chicks free range liquid egg white will keep in the refrigerator for 7 days.