Separate the egg whites and yolks into two different clean bowls.

Season the yolks with a pinch of salt and pepper, then whisk them vigorously until they are smooth and slightly pale.

Using an electric hand mixer or a whisk, beat the egg whites until stiff, glossy peaks form (this creates the airy structure).

Gently fold the whisked yolks into the stiff egg whites using a spatula; be careful not to over-mix or the air will escape.

Melt the butter in a non-stick frying pan over low to medium heat, ensuring it coats the bottom evenly.

Pour the fluffy egg mixture into the pan and gently smooth the top with a spatula into a round shape.

Cover the pan with a lid and cook for about 4 to 5 minutes, or until the bottom is golden brown and the top is set but still jiggly.

Sprinkle the grated cheese and chopped chives over the top of the eggs.

Carefully fold the omelette in half using a spatula and slide it onto a warm plate to serve immediately while it is still puffy.