Heat a large skillet over high heat, and sear each side of the roast for 2-3 minutes each.**If your slow cooker has a browning setting, I would recommend using it for this step so you don't have an extra pan to clean.
Transfer browned meat to a CLEANED cutting board or work surface, and cut meat into large 4" pieces. This will help the meat cook faster and make shredding quicker once the meat is cooked.
Once the meat is done, transfer back to a CLEAN cutting board and shred with two forks. Transfer shredded meat back to slow cooker to keep warm for serving right away.