Chop the stems and leaves into bite size. Preheat a wok or skillet on high heat. When hot enough, add in the oil, swirl to cover the wok/skillet. Add in the garlic and saute for about 30 seconds. Add in the kale and oyster sauce and stir to mix everything. Pour in the chicken stock and cover. Let it cook for about 5 minutes, uncover. The kale will be somewhat soft, but still a bit crunchy. Drizzle in the sesame oil. Have a taste and season with a bit more salt if needed. Turn off the heat and sprinkle with sesame seeds and toss to mix. Serve immediately