Use your stand mixer to speed up the process. Place all ingredients in the mixer's bowl with the "dough hook" attachment. Start the machine at the slowest speed. Of course, you can knead the dough by hand if you prefer.
Once done, roll out the dough on the table (minimally sprinkling with flour) for a thickness of about 2 mm.
Cut the dough using a round cutter. Place a heaping teaspoon of filling on each of them, press edges together.
Bring a pot of salted water to boil. Reduce the heat to a simmer. Drop dumplings in and cook for 5-6 minutes until they float to the top.
Remove with a slotted spoon. Serve warm with melted butter.