Heat the butter in a large stock pot over medium-low heat. Add in the onion, carrots, celery and garlic with a big pinch of salt and pepper - I’d say at least ½ teaspoon salt and pepper to start. Cook, stirring occasionally, until the vegetables soften. Stir in the garlic cloves and poultry seasoning. Stir in the shredded chicken.
Add in 7 cups of chicken stock and the parmesan rind. Bring the mixture to a boil, then reduce it to a simmer. Stir in the star pasta. Cook uncovered, stirring occasionally, until the pasta is al dente, about 8 minutes.
Add in the lemon juice and fresh parsley. Taste the soup and if it needs more salt and pepper, add it. If the parmesan rind didn’t melt entirely, you can scoop it out at this point. You can also decide if you’d like to add the additional cup of chicken stock here - it depends on how hearty or how brothy you like your soup. The pasta will soak it up as it sits!
Serve immediately with a lemon wedge for sprinkling, parmesan cheese for topping and parsley sprinkled on top.
Note: if you want to prep this for meals ahead of time, or want to have it for leftovers, I suggest cooking the pasta separately as it will soak up most of the broth as it sits overnight. Combine the soup and pasta stars and reheat to enjoy!