(I did try and come up with a better title, promise.)
You know how when you try to spread mashed potato over the top of a pie, it can clump, or you end up getting bits of the pie mixture in with the potato, particularly if the mash has already cooled? (No? I wouldn’t bother reading the rest of this post in that case.)
Well, I think I have a solution. If you spread some of the mash round the side of the saucepan in which you mashed the potatoes (the inside, obviously), you can lift it out on a knife and just lay it over the pie, then repeat until the whole thing’s covered. Like laying turf on a lawn. But with mashed potato instead of turf. And pie instead of lawn.