Place the beef stew meat in the slow cooker. Season it lightly with salt and pepper.
In a small bowl, stir together the coconut aminos, minced garlic, grated ginger, 1 tablespoon of the sesame oil, beef broth, and red pepper flakes. Pour the mixture over the beef.
Cover and cook on low for 7 to 8 hours until the beef is fork-tender.
About 20 minutes before serving, cut the cauliflower into florets and pulse in a food processor until it resembles rice. Heat the remaining tablespoon of sesame oil in a skillet over medium heat. Add the cauliflower rice and cook for 5 to 7 minutes, stirring often, until it softens slightly. Season with salt and pepper.
Shred the beef lightly with two forks right in the slow cooker and stir it into the sauce.
Spoon the cauliflower rice into bowls. Top with the Korean beef, then finish with sliced green onions and sesame seeds.