You can also serve this omelette without spring onions.
Begin by beating up the eggs in a bowl until they are very well combined. Strain them through a sieve to remove any lumps.
Add in all the ingredients bar the vegetable oil. Mix well.
Heat up a large frying pan. It is better if you have a square or rectangular frying pan as this produces and omelette shape which is perfect for rolling, but a large round pan will do just fine too.
Coat the pan with vegetable oil.
Pour out omelette and lift the pan to spread the omelette around the surface. When you have coated the pan in a thin (1/2 cm) layer of omelette, you're ready to cook.
The omelette will cook very quickly as it is so thin, so be vigilant. when the bottom is completely cooked but the top is still a little runny, begin to roll the omelette up with a spatula. When completely rolled to one side, take more of the mixture and repeat the process to the side of the rolled omelette.
When the next layer of omelette is done, roll the last roll back over the new layer of omelette.
Repeat the process until you have used all of the egg.