In a bowl, combine the ground turkey, breadcrumbs, freshly grated parmesan, egg, parsley, diced onion, minced garlic, and salt. Mix gently with your hands until just combined—don't overwork the mixture or the meatballs will become dense and tough. Set aside while you start the broth base. I find that keeping my hands slightly damp helps prevent the mixture from sticking and allows for more delicate handling.

Heat the olive oil in a large pot over medium heat. Add the diced small onion and carrots, sautéing for about 5 minutes until they begin to soften and release their aromatics. This creates a flavorful foundation for the broth. Pour in the chicken broth and add the parmesan rind, then bring everything to a boil. The rind will infuse the broth with deep, savory umami throughout the cooking process.

While the broth comes to a boil, shape the turkey mixture into small, bite-sized meatballs (about the size of walnuts). Place them on a broiler pan or baking sheet and broil for 8-10 minutes until they're cooked through and lightly golden. I prefer broiling over pan-frying here because it keeps them from absorbing excess oil and maintains their light texture. The meatballs don't need to be perfectly browned since they'll continue cooking in the broth.

Once the broth is boiling and the meatballs are cooked, add the acini pasta directly to the broth and cook for about 5 minutes. Then add the cooked meatballs and the escarole, stirring gently to distribute everything evenly. Continue cooking for approximately 5 more minutes until the pasta is tender and the escarole is wilted. Taste the soup and season with pepper and additional salt as needed.

Remove the parmesan rind from the pot and discard it. Ladle the soup into bowls and serve immediately while hot. The soup is best enjoyed fresh, though it stores well in the refrigerator for up to 3 days.