Fill a large stock pot with 5¼ cups water and 5¼ chicken broth and heat over high heat.
Add onion, celery, carrots, garlic and season with ½tbsp of salt to the pot and bring to a boil.
Once boiling, reduce the heat to medium-low heat and semi cover the pot with a lid.
Allow the broth to continue to cook for 45 minutes or until vegetables are super soft.
Taste broth and if needed add more salt to taste.
Transfer vegetables with a slotted spoon into a blender along with two ladles of broth. Blend until smooth (about 1-2 minutes).
Return blended vegetable mixture back to pot and stir.
Meanwhile, bring a separate pot of salted water to boil and cook orzo. Once orzo is al dente drain pasta into a colander.
Add a ladle of the cooked orzo to a serving bowl and then pour broth on top.
If using garnish with fresh Italian parsley and dust with parmigiano. Enjoy!