Place cold left over mashed potatoes in large mixing bowl.
Add eggs and flour and beat until totally incorporated.Here's where you start experimenting if you like. They're good plain, lightly salted and peppered after cooking but sometimes you just have to mix it up. I personally like to make them somewhat like twice baked potatoes by adding sour cream, cheddar cheese and bacon pieces. I've also been known to add blue cheese and bacon. I live for bacon... hmmmmm...
Heat oil or grease over medium heat and place approximately 1/4 cup of potato mix in heated oil and fry for approximately 5 to 7 minutes per side until lightly browned and crispy exterior with fluffy interior. Best way to test this is to eat one while no one is looking. Just saying. These will be super tender and it is important to be gentle when turning.