Preheat the oven to 350 degrees F.
For the meatballs, place the ground chicken, sausage, bread crumbs, garlic, parsley, Pecorino, Parmesan, milk, egg, 1 teaspoon salt, and 1/2 teaspoon pepper in a bowl and combine gently with a fork. With a teaspoon, drop 1 to 1 1/4-inch meatballs onto a sheet pan lined with parchment paper. (You should have about 40 meatballs. They don't have to be perfectly round.) Bake for 30 minutes, until cooked through and lightly browned. Set aside.
at 7:05 AM on Jul. 7, 2011