1. Prepare a steamer with boiling water. Place the bok choy, garlic, ginger, and red pepper flakes in the steamer and steam until the leaves begin to go limp, about 30 seconds. This will keep the stem crunchy.
2. Remove the bok choy and place in a serving bowl. Combine the soy sauce, water and sesame oil. Pour the mixture over the bok choy and serve immediately.