Heat a large Dutch oven or soup pot over medium heat. Add the oil, butter, onion, shallot, celery, and bell pepper and stir to combine. Cook for 4-5 minutes or until the onions are translucent, stirring occasionally. Add the garlic, stir well, and cook for another 2 minutes.

Add the broth, carrots, parmesan rind (if using), and salt. Bring the mixture to a boil then reduce to a steady simmer and cook for 20-25 minutes (uncovered) or until the veggies are nice and tender.

Remove the parmesan rind, if you used one. With a slotted spoon, remove 2 cups of the diced veggies and set aside.

With an immersion blender (or a regular blender) puree the broth/veggie mixture in the pot until smooth.

NOTE: If you use a regular blender, be sure to let the mixture cool down a bit before blending. Also, remove the center cap on the blender top and cover it with a clean kitchen towel or several thicknesses of paper towels. This will allow the heat to vent and prevent it from building up.

Add the pasta, bring the mixture to a boil then reduce to a steady simmer. Cook, uncovered for whatever the time on your bag or box of pastina instructs. (Acini de pepe takes 9 minutes.)

Add the rotisserie (or leftover) chicken and the reserved veggies. Stir to combine. Cover and allow the soup to rest for 20 minutes.

Taste the soup and adjust the seasoning, adding more salt if needed.

Serve with grated parmesan, a scatter of finely chopped fresh rosemary or fresh thyme leaves (or both) and fresh ground black pepper. Enjoy!