1. Finely chop the tomato concassé.
2. Using your hands, tear the basil leaves into smaller pieces and mix with the tomatoes in a bowl.
3. Season with salt and pepper.
4. Break the eggs into a tea cup, remove any unwanted shell and transfer into a larger bowl.
5. Season with salt and pepper and beat the eggs together using a fork or whisk.
6. Over quite a high heat, heat the omelette pan and add the butter and oil (the oil should stop the butter from burning).
7. When the butter begins to bubble well, pour in the beaten egg mixture.
8. Cook the egg mixture quickly, keeping the pan moving with one hand and stirring with a fork or spatula with the other, not allowing the mixture to settle and not letting it to overcook.
9. Check if it is done when it is still a little runny on top (‘baveuse’).
10. Remove from the heat.
11. Using the fork or spatula, fold the omelette and carefully turn out onto a warm plate.
12. Make in incision almost the length of the omelette, fill it with the tomato and basil mixture and serve.