In a large saucepan, bring the broth and ginger to a boil.
Add the pot stickers and carrots and simmer until just tender, 8 to 10 minutes.
Add the mushrooms and edamame and simmer until heated through, about 2 minutes.
Stir in the watercress, soy sauce, and ½ teaspoon salt. Sprinkle with the scallions before serving.