As I didn’t have pictures of turned I thought I’d post pictures of my first practice session one quiet Friday night (Fridateless night! Sob!)
Bought a big bag of potatoes. I believe this was a 2kg bag.
one 2kg bag of potatoes
Get 2 big bowls or pots. Peel potatoes. Put peeled potatoes in one pot of water and use the other for the turned potatoes. Generally, when cooking potatoes, you should soak them in water to prevent them from turning brown (there are exceptions, if you don’t want to lose the starch, but you gotta work fast!).
Cut into approximate dimensions for required size.
Peel and cut into approximate required dimensions.
Use the turning knife to shape the potato chunk
A little too fat actually
But not too bad for a first attempt.
There was more trimmings than turned potatoes
This is all I got from 2kg of potatoes.
Shape or “turn” with turning knife. The motion is similar to following the contours of an egg from top to bottom.
1 large potato could yield around 4 turned potato pieces. But there is inevitably a lot of waste.
Anyway, i couldn’t take pictures and turn the potatoes, so this is not the best step-by-step at all, but more just to show what was involved.
After much manipulation, and muscle-cramping, the turned spud!
Et voila!
elceebee 
Quite wasteful hor?
Yes, I think so too. Although we are always told to keep the trimmings for stock, etc, but really, not always feasible.