Preheat oven to 350F.
Peel and deseed squash. Chop onion, carrots, celery, and squash into bite-sized chunks, season with sea salt, and place on a lipped baking sheet lined with parchment. Roast with the whole head of garlic for about 45 minutes, or until the vegetables start to soften.
Shred chicken and add with chicken broth into a stock pot. Mash roasted garlic and mix with some of the chicken broth to make a thin paste.
Add garlic paste and roasted veggies into the soup; cook on low for 30 minutes to 1 hour.
Mince kale and herbs finely and add to the soup; allow them to brighten for a minute or two. Season with additional sea salt and freshly ground pepper, ladle into bowls, and serve.