For the soufflé, preheat the oven to 200C/400F/Gas 6.
Place the tomato on a non-stick baking tray.
Whisk the egg white until stiff peaks form where the whisk is removed.
Mix the egg yolk with the cheese and season to taste with salt and freshly ground black pepper.
Gently fold the egg white into the cheese mixture and spoon into the tomato cavity.
Bake in the oven for six minutes, or until risen and set.
For the salad, place the courgette and herbs in a bowl.
Mix together the oil and vinegar and stir through the salad.
Serve the souffléd tomato immediately on a plate beside the salad.