Add the mashed potatoes to a large bowl. If you need to make mashed potatoes see the recipe link above. Flatten them out to make sure they are even then divide them into 4 equal parts. Remove one of the parts and set it aside.
1.5 lbs mashed potatoes
Fill the whole you created with flour to make it even with the rest of the potatoes. For me, this was roughly 1 cup of flour. Add one egg and the remaining potatoes that you removed earlier.
1 egg, 1 cup all-purpose flour
Before you get your hands dirty, fill a medium pot ¾ of the way with water, add the salt and set it to boil.
½ tbsp salt
Stir the potatoes, flour and egg to combine. You can use a stand mixer, a spatula or your hands.
Once the dough forms into a manageable ball (it will be a bit sticky) you are ready to make the dumplings.
Coat a clean surface with flour. Knead the dough a couple of times just to bring it all together. Divide into 5 pieces. Take one of the 5 pieces and roll it out into a long strip. The strip should be about 1” across.
1 cup all-purpose flour
Once you have the right diameter, using your hand pat it down gently to turn the roll into a flat strip. Then cut it using a butter knife into 1.5” dumplings. Repeat for the remaining dough. I got 66 dumplings in total.
Once the water comes to a boil add some dumplings to it and boil for 3 minutes. Do not overcrowd the pot. You want the water to keep boiling as you add dumplings and you don’t want them to stick together. Once the dumplings float to the top, they’ll need another 90 seconds or so and they’re ready. Do not overcook them or they will start falling apart.
Scoop them out using a slotted spoon into a bowl and add some butter. Toss to coat. This will prevent them from sticking to each other.
2 tbsp butter
Serve immediately.