1. In a 4- to 6-quart slow cooker, combine the tamari or soy sauce, honey, vinegar, toasted sesame oil, garlic and chili pepper. Add the short ribs.
2. Cook, covered, on high for about 6 hours (or on low for about 8 hours), until the meat is tender and easily pulls away from the bone. (If you can, move the short ribs around in the crockpot a few times during cooking so they all cook evenly.)
3. Remove short ribs from slow cooker and set aside to cool. Skim the fat from the cooking liquid and discard, then transfer the liquid to a pot on the stove. Bring to a boil, then reduce heat to a simmer and cook until the liquid has reduced and thickened, about 15 minutes.
4. Pull meat off the rib bones with your fingers or with a fork and place into a bowl. Add the reduced liquid to taste (if there is a lot left over, you can serve the rest of the sauce on the side). Transfer meat to a serving dish or bowl and garnish with the toasted sesame seeds.