Preheat over to 350 degrees F.

Make barbecue sauce: In a medium sized bowl, add the arrowroot powder, brown sugar, apple cider vinegar and broth. Stir to combine, using a blender if necessary to fully incorporate the arrowroot powder. Once combined, stir in the tomatoes and set mixture aside.

Pat brisket with paper towels. Patting the brisket with paper towels removes excess surface moisture from the meat. When searing any cut of meat, you want the surface to be as dry as possible. If the meat is damp or wet, that moisture prevents the meat from browning well and developing that nice crispy sear.

Season the brisket generously with salt and pepper.

In a large, heavy pot (I used my Dutch oven), over medium-high heat, warm the avocado oil. Once hot, add the brisket, fat side down, and sear the meat on both sides. This will take about 10 minutes. Note: If you cannot fit the whole brisket in your pot or Dutch oven, you may need to cut your meat in half and repeat this one or two times. Transfer seared meat to a plate.

Pour off all but 2 tablespoons of fat from the pot. Add the onions and sauté over medium-high heat until softened, approximately 3-5 minutes. Once soft, add the minced garlic and ground allspice. Sauté for 30-60 seconds.

Add the broth mixture made in step 2. Stir to combine. The add the brisket back to the pot (or use a roasting pan if brisket is too large for your Dutch oven or pot). Cover the pot with a lid or foil and cook in the oven until the brisket is very tender – about 3 to 4 hours. Rotate the meat once halfway through the cooking process. Notes: You will need to add cooking time for a larger piece of meat. If your meat is too tough, cook longer to break down the connective tissue and make it nice and tender.

After removing from the oven, skim the fat off the surface cooking liquid.

Taste the sauce and adjust salt and pepper as needed.

Let the brisket cool slightly in the cooking liquid, then transfer to a cutting board and cut or shred to your liking.