You can buy instant mashed potatoes at Hypermart. Same isle as the pancake mix I think. Just saw it there today.
Re: Instant Mashed Potatoes. Davy is right, but i'd cut them into smallish pieces so they cook faster, boil in a pot instead of a pan, and they are fantastic. BUT IF YOU MUST have instant, try the Deli at Why Not, pretty sure that's where we found some a couple months ago. Only problem was had to translate the german instructions. Gut & Gunstig's Kartoffel Puree....