Chop the spring onion and coriander quite finely and beat the eggs together with salt and pepper. Heat the oil in a small frying pan then tip in the onion, coriander and chilli and stir round the pan for a second or two so they soften a little. Pour in the eggs and keep them moving until two thirds have scrambled.
Settle the eggs back down on the base of the pan, scatter over the cheese and cook for about a minute until the omelette is just set and the cheese has melted.
Carefully fold the omelette using a palette knife and slide from the pan to a serving plate. Eat while the omelette is hot and the cheese still melted.