Cook the chicken and shred, set aside.
Heat oil in a large soup pot or dutch oven on medium-high heat. Saute carrots, celery and onion until onions are translucent, about 5 minutes.
Add mushrooms and garlic and cook for another 3 minutes.
Stir in chicken stock and water, herbs, bay leaves, mace blade or nutmeg, salt, and pepper.
Bring to a boil, add chicken, cover and reduce heat and simmer for 15 - 20 minutes.
Discard herbs, bay leaf, and blade mace.