Heat olive oil in a large sauté pan on medium high heat. Add onions, then garlic, then bok choy. Sprinkle with sesame oil and salt. Cover, and let the baby bok choy cook down for approximately 3 minutes. (Like spinach, when cooked, the bok choy will wilt a bit.).
Remove cover. Lower heat to low. Stir and let cook for a minute or two longer, until the bok choy is just cooked.