Steam or microwave the dumplings as the label directs.
Bring the heavy cream to a boil in a large skillet over high heat. Add the dumplings and cook until the cream is slightly thickened, 2 to 3 minutes. Add the peas and cook until warmed through, about 1 minute. Remove from the heat, add the parmesan and season with salt and pepper. (The sauce may seem thin but it will thicken as it stands.)
Divide the dumplings and sauce among plates. Top with the scallions and more parmesan.