Whisk the eggs until fluffy, add in the chopped chives (if using) and a pinch of seasoning.
Warm the oil in a frying pan over a medium heat and pour in the eggs. Move the pan around to ensure that the eggs spread out over the base of the pan and cook for a few minutes. Flip the omelette and cook for a few minutes more.
Add the toppings to the omelette then either finish up underneath a hot grill before folding over, or cook a minute or so more in the pan before turning over into a semi-circle and serving. Enjoy!