Pour marinara sauce in a pot over medium-low heat.
In a large bowl, combine ground turkey, breadcrumbs, egg, parsley, garlic, and Parmesan; using your hands, mix well until everything is combined. Then, using 1/8 cup at a time, form the mixture into small meatballs (about the size of ping pong balls).
Add the meatballs to the sauce and cook 20 minutes or until cooked through.
Meanwhile, steam green beans.
Serve sauce and meatballs over pasta with green beans and grapes on the side.