Brown the beef and onion in a skillet over medium-high heat for 8 to 10 minutes, crumbling the meat until it reaches 160°F.
Drain the fat and stir in the garlic, ginger and gochujang for 30 seconds.
Transfer the mixture to a 6-quart crockpot and add the soy sauce, tomatoes, beans and broth.
Cover and cook on low for 5 to 6 hours until the beans are tender and the broth has thickened.
Stir in the rice vinegar and sesame oil, then add up to 1 additional tablespoon gochujang only if the chili tastes mild.