Place the turkey thighs, baked beans, onion, barbecue sauce, yellow mustard, cumin, and salt into a slow cooker. Set the cooker to Low, and cook 10 to 12 hours. Remove the turkey thighs, and shred meat using 2 forks. Discard bones. Return the shredded turkey meat to the slow cooker. To serve, place about 1/2 cup of shredded turkey and sauce onto each potato roll.
