The key is to use warm mashed potatoes, don't add any extra milk than what you would in your regular mashed potatoes, and i would even hesitate using too much extra butter than what you would in your mashed potatoes.
You'll add flour in gradually until the potatoes start to bind in a ball as you mix it with a spoon.
Once your potatoes are a non-sticky mound, you could add your 'extras', like scallions or shredded cheese, or diced ham.
Flour your surface and your rolling pin and then roll out small balls of the potato dough to a flat circle.
Prick the flat cake with a fork, this will make them fluff a bit more (which is how i like them!)
Make sure your frying pan or flat griddle is on high heat and add a little oil to the pan. I flour my spatula tip before trying to pick the potato cake up from the counter.
Fry on each side until nice and dark golden brown. You can press on the cake once flipped to flatten a bit more and cook the gooey middle to your liking.
Serve with butter, or even nice with a little real maple syrup (although not traditional).... And to be truly a modern day Scot, must enjoy with a morning glass of Irn Bru! Enjoy!
Notes
** FLOUR - I used self-rising, but if using all-purpose flour, add 1/4 tsp salt and 1 Tablespoon baking powder per cup of flour. (thanks to reader Kay for that tip!!)