Wash and chop the onion, tomato, green chili, and cilantro. Combine them in a bowl for the omelette mixture.

Add salt and black pepper to the vegetable mixture and combine well with a spoon.

Heat oil in a frying pan over medium heat. Pour in the egg mixture and cook for 3-4 minutes until slightly firm. Flip and cook for an additional minute.

Serve the omelette hot, garnished with freshly chopped cilantro. Pair it with toast or a side of salad for a complete meal. Store leftovers in an airtight container in the fridge for up to 2 days, and reheat before serving.