Fill a large bowl with water and ice. Set aside.
Trim ends from Chinese broccoli, then cut in half crosswise, separating the leaves from the stalks. If any stalks are thick, cut them in half lengthwise.
Heat about 4 inches of salted water in a large lidded pot or wok, bring to boil. Add the stems and cook for 2 minutes. Add the leaves and cook for 3 minutes more (stems should be tender but not mushy).Transfer broccoli to ice bath.
While the broccoli cools, prepare the dressing. Combine ginger, ponzu sauce, lemon, soy, and chili sauce in a small bowl, then slowly drizzle in the sesame oil, whisking constantly. Set aside.
Drain the broccoli and dry well (in a salad spinner or with a clean kitchen towel) then transfer to a serving bowl. Drizzle dressing over broccoli and toss to coat evenly. Sprinkle sesame seeds and serve.