Mum had a stock answer....

....whenever I asked her how long my latest new food experience would take to cook:

"Until it's done".

Which is fair enough really. I mention this solely because I stumbled upon another bit of Mum's wisdom - serving as a bookmark on an old cooking book:

Boil : Wija, Estima
Chip : Maris Piper
Roast : King Edward, Desiree
Baked : Cara
Mash : King Edward, Romano

So now you know what to do with your spuds.