Using a large pan, heat the avocado oil over medium heat. Add the roast, season with salt and pepper, and sear for 2-3 minutes on each side or until lightly browned. Remove from the pan and place on the bottom of the slow cooker.
Add the onion and garlic to the pan and saute for 3-4 minutes or until slightly translucent. Remove from the pan and add to the slow cooker.
Add the parsnip, carrots, rosemary, thyme, bay leaves, broth, coconut aminos, and balsamic vinegar to the slow cooker. Place the lid on the slow cooker and cook on low for 7 hours.
Once finished, whisk in the arrowroot starch with about a tablespoon of water until fully combined. Add back to the slow cooker and allow to cook for another hour.
Turn off the slow cooker and remove the bay leaves.
Serve the roasted shredded along with the vegetables and top with several spoonfuls of the broth. Top with chopped parsley.