1 1/2 pounds baking potatoes, peeled and cut into chunks
4 to 5 tablespoons unsalted butter + a little extra to melt and drizzle over the dumplings (Deb note: I was able to make do with just 2 T butter in a non-stick)
3 onions, finely chopped
Salt and black pepper to taste
1 to 2 packages of gyoza (pot sticker) wrappers
3 to 5 green onions, thinly sliced or 1/4 cup chopped chives or 2 tablespoons chopped parsley or additional fried onions (see note), to serve

Sour cream, melted butter or vinegar to serve