Cook the pasta according to the instructions with a strong dash of olive oil until it is firm to the bite, then drain.
In the meantime, clean and wash the tomatoes (leave whole!). Stone the olives, drain the mozzarella and cut into pieces approx. 2 x 2 cm.
Make a marinade from the pesto, the olive oil (do not use everything), strong pepper and carefully salt.
Mix the pasta with tomatoes, olives and cheese, pour the marinade on top and carefully fold in everything. Let it steep for at least 1 hour, preferably overnight. Cut off the basil leaves and fold them into the salad just before serving. Again vigorously with the pepper mill over it.