In a non-stick frying pan, heat the olive oil and add the onion. Cook and stir for a few minutes until soft. Add the cherry tomatoes and cook for a few minutes, stirring often, until they begin to loose shape and soften.
In a bowl whisk the eggs with the salt and pepper then pour into the frying pan. Cook the egg, stirring occasionally, until set. Transfer to a plate and serve with fresh basil sprinkled on top.