Begin by adding olive oil, onion, celery, and garlic to a dutch oven or soup pot. Heat to medium-high and saute until the onion, celery and garlic start to "sweat" and get soft (about 5 min).
Add chicken broth, chicken, bay leaves, carrots, mushrooms, parsley, rosemary, spinach and Old Bay seasoning. Heat to boiling and boil for 10-15 minutes.
Add water, egg noodles, salt and pepper. Cook noodles according to package directions (about 8 minutes or so).
Serve immediately. Refrigerate any leftovers for up to one week.