Thoroughly rinse the quinoa in a fine-mesh sieve or colander.
Bring the water to a boil in a large saucepan. Add the quinoa, return to a boil, and cook over medium heat for 10 to 12 minutes, uncovered, or until the quinoa has absorbed most of the water, stirring occasionally.
Remove from the heat, fluff with a fork, cover, and let stand for 5 minutes.
While the quinoa cooks, bring a large stockpot full of water to a rolling boil (if you're opting to boil the dumplings—if you're pan-frying, skip this step), and prepare the veggies and other quinoa add-ins.
Transfer the cooked quinoa to a large bowl and stir in the edamame, peppers, cabbage, scallions, cilantro, sesame seeds, sesame oil, and salt. Set aside.