Combine kohlrabi, carrots, and beans in a large bowl. Toss with sugar and let sit for 10 minutes. Drain any water that has accumulated in the bowl. Add rice vinegar, soy sauce, sesame oil, garlic, chile, and cilantro stems. Toss and let sit while you pan-fry the dumplings. At the last minute, add cilantro leaves to the slaw. Garnish with sesame seeds and serve with pan-fried dumplings.