In a small bowl, mix together the tamari, sesame oil, hoisin sauce, and mirin to create the sauce.
Heat the olive oil in a large, deep pan over medium-high heat. Add the minced garlic and sauté for about 30 seconds.
Add the ground beef to the pan, breaking it up with a spatula or wooden spoon. Cook for 3 to 4 minutes until the beef is browned and fully cooked.
Pour the prepared sauce over the beef, stirring to combine. Let it cook for 2 to 3 minutes until it thickens slightly.
Push the beef mixture to the edges of the pan, creating a space in the center. Place the ramen noodles in this space.
Pour the water over the noodles. It's fine if the noodles are only half-submerged. Cover the pan and cook for 1 minute.
Remove the lid and use tongs to turn the noodles. Cover again and cook for another minute or until the noodles are just pliable.
Take off the lid and add the sliced bok choy and bean sprouts. Toss everything together with the tongs until well mixed.
Continue to cook for 1 minute, tossing occasionally, until the vegetables are slightly softened and the noodles are fully cooked.
Serve the dish immediately, garnished with sesame seeds, chilli oil crisp if desired, and sliced spring onion.
