Put the acorn squashes in the oven WHOLE at 425 degrees for 1 hour. When you take them out, cut them in half and let them cool to touch while you start making the soup.
Sautee the onion, carrot, celery, and potatoes in the butter with a few big pinches of sea salt to bring out their juices and sweeten. Cook on medium/high for about 10 minutes.
While the veggies are cooking puree the roasted squash in your processor or blender with a little of the bone broth to be sure it gets fully pureed.
Add the garlic to the pot and cook for a minute.
Add the flour to the pot and cook for a minute.
Add the squash puree, bone broth, chicken, and spices to the pot and bring to a simmer for about 5 minutes.
Add the spinach to wilt in and then season sea salt/pepper to taste.