Preheat the oven to 400°F (200°C). Slice off ~¼ inch of the top of a garlic head, sprinkle salt and olive oil, and roast for 35-45 minutes until the cloves are golden, completely soft, and caramelized.
Once roasted, allow the garlic to cool slightly, then squeeze the cloves out of their skins, and mash with a fork into a smooth paste, and set aside.
Next, pat dry the chicken, coat with the seasoning, and sear in a Dutch oven with a tbsp olive oil over medium heat until golden and the internal temperature reaches ~165°F (74°C). Shred and set aside.
Reduce the heat, add a tbsp each of olive oil and butter, then add the onion, carrot, celery, and sauté for 5-6 minutes until the veggies are softened.
Add the chopped fresh garlic, cook for 45 seconds, then add the mashed roasted garlic, mix, and cook for another 30 seconds.
