Begin by washing and roughly chopping the carrots, celery, and onion into small pieces. Set them aside as they will form the flavorful base of your Italian Pastina Soup.

In a large pot over medium heat, combine the chopped vegetables with your chosen chicken or vegetable broth, along with a Parmesan rind for added flavor. Bring the mixture to a high boil, which should take about 5-7 minutes.

Once boiling, reduce the heat to low and cover the pot with a lid. Allow the soup to simmer for 15-18 minutes, checking occasionally.

After simmering, carefully remove the pot from the heat. Strain the cooked vegetables and liquid into a bowl, keeping the broth. Blend the vegetables in batches using a blender or an immersion blender until smooth.

Return the pureed vegetable mixture back into the pot. Pour in the remaining broth and bring the soup to medium heat again. Add the pastina or your choice of small pasta, then simmer for 7-9 minutes until the pasta is cooked al dente.

When the pastina is perfectly tender, remove the pot from heat and season your Italian Pastina Soup with grated Parmesan, salt, and black pepper to taste.

Ladle the soup into bowls and garnish with freshly chopped parsley, if desired.