Peel onion and cut in half, roughly chop celery
Add onion, celery, carrots and peeled garlic to a large pot, cover with enough water (roughly 4 cups) and bring to a boil
Once boiling add raw chicken breast, cover and cook for 25 minutes
Remove chicken and shred
Remove vegetables and add to a blender with 1/2 cup of the liquid, blend until smooth
Add vegetable mixture back into pot along with bone broth, pastina and parmesan rind if using
Let simmer for 15 minutes
Add shredded chicken and cook for another 5 minutes
Remove parmesan rind
Serve with lots of shredded parmesan cheese, a squeeze of lemon juice and lots of black pepper