1) Place the peeled potatoes in a pot of cold water. Put enough water in it so that it covers the potatoes. Sprinkle a little salt into the pot. Heat the water until it is boiling. Let boil for 20-30 minutes until potatoes are soft. You can test the consistency by poking a fork in them and if it goes through easily the potatoes are done.
2) While the potatoes are cooking. In a large mixing bowl, place the 3 cups of flour. move the flour so there is a dip in the center like a hole. Pour the beaten eggs into the hole. Take a fork and slowly pull some flour from the edges of the hole into the center. Mix with the eggs. Continue pulling flour from around the edges and mixing it into the eggs. As you do this, the egg and flour will combine to make the dough. At some point, you'll have to abandon the fork and just dig in with your hands. If your dough is too dry add a tablespoon of oil, if the flour is too wet has 1/2 a cup of flour. Kneed the dough until it is smooth and elastic. Break the dough into two balls. Wrap in saran wrap and place in the fridge for 30 minutes.
3) Drain the potatoes. Place in a large bowl and add milk and butter. Use a mixer or a hand beater to mix in a smooth mixture. It is ok if there are some lumps, but I like mine mostly smooth. Let cool.
4) After 30 minutes bring out one ball of dough. Roll out on a floured surface so that it is about a 1/4 inch thick. Use a circle cookie cutter or a plastic cup to cut the dough into circles. Lay the circle in one hand, scoop a teaspoon of potato mixture into the center of the circle. Dip your finger into water and wet the edges of half the circle. Close the circle around the mixture to make a half moon shape. Press the edges together to seal. The water helps seal the dough so don't forget it. Place the perogie on a floured baking sheet.
5) When you have 10 perogies made drop them into salted boiling water. Stir gently. When the perogies float take them out and serve with sour cream, fried onions, bacon bits, cheese sauce or any of the before mentioned.
6) If you want to freeze your perogies, after boiling them, place them on a baking sheet to cool and dry. When perogies are dry (about 30/40 minutes) place into a freezer bag and seal. To reheat, just place frozen perogies into boiling water until they float abou 10 minutes.