Heat 1 tablespoon (15 mL) olive oil in a large wok or skillet over medium-high heat. Add cauliflower rice. Season with salt and pepper. Cook for 3-5 minutes, until tender. Remove from heat, divide among 4 bowls, and cover to keep warm.
In a small bowl, whisk together the coconut aminos, beef broth, sesame oil, ground ginger, and red pepper flakes. Set the sauce aside.
Turn the heat back on to medium-high. Add another tablespoon (15 mL) olive oil to the pan. Add the ground beef and season with sea salt. Cook for 8-10 minutes, breaking up with a spatula and stirring occasionally, until browned.
Push the beef to the sides of the pan, and add the minced garlic in the middle. Saute for about 1 minute, until fragrant, then mix into the beef.
Pour the sauce over the beef. Bring to a boil, then reduce the heat and simmer for 3-4 minutes, until the sauce is reduced and mostly absorbs into the meat. There won't be much liquid left.
To assemble your Korean beef bowls, top each bowl of cauliflower rice with ground beef. Fan out the cucumber slices, and sprinkle with sliced green onions and sesame seeds.
