Heat a 2 TBSP of sesame oil in a skillet or wok over medium-high heat. Once the oil is hot, carefully place the baby bok choy in the pan, cut-side down. Let the bok choy sear for about two minutes or until the cut side of he bok choy has browned. (Work in batches if you need to. Overcrowding the pan will rob it of it's high heat.)
When each bok choy is browned on its cut-side, remove the bok choy from the pan and set aside. Add the garlic and ginger to the pan, and add another TBSP of sesame oil if needed. Simmer for about 2 minutes.
Add the soy sauce and water to the skillet. Bring the liquid to a simmer for about 30 seconds to create a sauce.
Place the baby bok choy back into the pan, still cut-side down, and let the bok choy bathe in this glorious sauce until the leafy tops are wilted and the crunchy stalks are tender, but still crisp. This should only take about 2 minutes.
Plate the baby bok choy, cut-side up. Drizzle any leftover pan juices over the stalks, sprinkle with sesame seeds, and serve.