Preheat the oven to 350 F.
Trim any excess fat off of the brisket, leaving about 1/4" of fat.
Using a large cast-iron casserole dish, heat over medium heat and add the olive oil. Sear the brisket for 3-4 minutes on each side to lightly brown and generously season. Transfer the brisket to a clean surface.
Using the same pan, saute the carrots, onions, and garlic for 5-6 minutes or until lightly softened. Push the vegetables to the edge of the pan, making space for the brisket.
Add the brisket to the pan and top with coconut sugar, tomato sauce, and parsley. Pour the broth and vinegar into the base of the pan, add the bay leaves and cover the pan.
Transfer to the oven and roast for 2 hours. Reduce the oven heat to 300 F and roast for another 1 1/2 hours.
Remove the brisket from the oven and allow to rest before slicing and serving with the side of the vegetables, and topping with the cooking juices.