Preheat large pot on medium-high heat and add butter and olive oil. Add onion, garlic, carrots, celery and saute for 5 minutes, stirring occasionally. Add Italian seasoning, salt, pepper and saute for another 30 seconds, stirring few times.
Add chicken breasts and chicken broth, cover the pot and bring to a boil. Reduce heat to low and simmer for 15 minutes.
Add orzo pasta, stir and simmer for another 10 minutes, stirring a few times to prevent pasta from sticking.
After remove chicken breasts on a plate and shred with 2 forks. Return shredded chicken to the pot along with lemon juice, parsley and cream, if desired. Stir and adjust any seasonings to taste.
Serve soup hot with a slice of crusty bread.
Notes
Store: Refrigerate soup leftovers for up to 4 days. Pasta will keep absorbing the broth as it sits in it, so more likely you will have to add more chicken broth when reheating. Do not add water as it will dilute the flavor of orzo lemon chicken soup.Freeze: Freeze leftover soup in an airtight container, leaving some room for expansion. Again I recommend to freeze soup without pasta if possible as pasta does not freeze well.