1. Prepare the vegetables by dicing the carrots and celery, slicing the mushrooms, and chopping the onion.
2. Place the chicken breasts at the bottom of your slow cooker.
3. Add the prepared vegetables on top, along with the wild rice blend.
4. Pour in the chicken broth and water, and sprinkle the garlic powder, thyme, parsley, salt, and pepper over the mixture.
5. Cover the slow cooker with its lid and set it to cook on low for 6-7 hours or on high for 3-4 hours.
6. Around 30 minutes before the cooking time is up, remove the chicken from the slow cooker, shred it using two forks, and place it back into the soup.
7. Mix the heavy cream and flour together in a bowl, ensuring no lumps remain, and stir it into the soup to thicken it.
8. Let the soup cook for an additional 30 minutes or until it reaches the desired thickness.
