Season the roast with salt. Brown it in the oil in a hot skillet for 4 minutes per side and transfer it to a 6-quart slow cooker.
Whisk the broth, soy sauce, vinegar, brown sugar, ginger, garlic and sesame oil. Pour it around the beef.
Cover and cook on low for 6 hours. Tuck the cabbage wedges around the roast, cover again and cook for 1 1/2 to 2 hours until the beef and cabbage are tender.
Transfer the roast and cabbage to a platter. Skim the sauce, stir in the cornstarch slurry and cook on high for 10 minutes.
Slice or pull the beef and return it briefly to the sauce. Divide the rice among bowls and add beef, cabbage and a modest spoonful of sauce.