Separately toss the diced celery root, sweet potatoes, and parsnips each with 1 tablespoon of avocado oil. Place on a baking sheet, divided. Season with salt and pepper and roast for 25 minutes, until tender and caramelized. Remove from the oven and set aside.
Heat 1 tablespoon of avocado oil on medium heat in a heavy-bottomed 4-6 quart pot. Season 1 pound of chopped chicken thighs with salt and pepper.
When the oil starts to shimmer, add the chicken thighs and cook until browned all over. Add the 1.5 cups of diced onions and sauté for 8 minutes, until translucent and tender.
Next add the roasted root vegetables. Cover with 4 cups of chicken bone broth, and bring to a simmer then finish with 1 teaspoon each grated garlic, turmeric and ginger. Season with salt and pepper to taste.