Quarter the cherry tomatoes, chop the drained mozzarella and rocket into small pieces, mix everything. Add balsamic vinegar, pepper and salt to taste (do not forget the amount of pasta when salting, so use a little more salt or season later) and mix in a good dash of olive oil. Cook the spaghetti al dente. Mix with the other ingredients (the mozzarella won`t stick when the pasta has cooled down a bit).