Trim and discard the rough bottoms from the baby bok choy. Separate the leaves, rinse, and pat dry.
In a small bowl, combine the soy sauce, rice wine, and sugar. Set aside.
Heat a wok or large skillet over medium-high heat until a bead of water sizzles and evaporates on contact. Add the peanut oil and swirl to coat the bottom and sides. Add the garlic and ginger and stir-fry until aromatic, 20 to 30 seconds.
Add the bok choy and stir-fry for about 2 minutes, until crisp-tender. Add the soy sauce mixture and cook for another 30 seconds. Turn off the heat, and drizzle with sesame oil.