Heat olive oil in a large stock pot over medium heat. Dice onion, celery, carrots, and garlic. Add to pot and cook for about 5 minutes or until onions and celery become translucent.
Add chicken broth, water, rosemary, italian seasoning, onion powder, salt and pepper to the veggies. Bring to a boil then reduce to a simmer. Allow to simmer for 10 minutes.
(OPTIONAL): At this point, I strained the veggies out of the broth and pureed them, adding half of the puree back to the broth-- a good way to hide veggies from picky eaters!
Add in the heavy cream and return to a simmer. Add tortellini to the pot, and allow to cook for about 3 minutes, until just al dente. Turn off the heat/remove the pot from the burner
Stir in grated parmesan and chopped parsley. Serve immediately.
