The tablespoon of cottage cheese in the meatball mixture is the detail that keeps ground chicken meatballs moist and tender rather than dense and dry. Ground chicken has very little fat and needs the extra moisture. It's completely undetectable in the finished meatball.
Brown the meatballs in batches without crowding the pan. Crowding drops the temperature and produces steamed grey meatballs rather than golden browned ones. A good sear on each meatball adds significant flavor to the finished dish.
Keep extra broth nearby during the pasta cook. Different brands of dried cavatelli absorb at different rates and some need more liquid than others to cook through properly. Add it gradually rather than all at once.
Stir the pasta around the meatballs every few minutes rather than constantly. Frequent stirring keeps the cavatelli from sticking to the bottom without breaking up the meatballs that are nestled in the sauce.