Combine the first 7 ingredients in a large bowl, mix well and marinate in the refrigerator for about half an hour.
Bring the water to the boil in a saucepan, stir in the couscous & briefly bring to the boil. Remove from heat, cover and let steep for about 5 minutes. Then loosen up with a fork and let cool down.
Add the cooled couscous and basil to the tomato-mozzarella mix and mix carefully. If desired, you can add some chilli - in powder form or fresh - to it.