Something like cottage pie, but with potatoes.

Hey here we have "pâté chinois", which is pretty similar,
ground beef (mixed with onions) on the bottom layer, canned corn (either whole-kernel, creamed, or a mix) for the middle layer, and mashed potatoes on top.

But as i am vegan, i replace the meat by lentils. it's delicious, mainly because i am a fan of potatoes!

all of these are similar to the variants my mother made me growing up and called it "sheperds pie". It didn't have bits of roast in it, tough, it was usualy ground meat, sometimes with the onions, as mentioned; the middle was pea one time, pea and carrot another time, mixed frozen, broc and caul; the topping was always just mashed potatoes for us. I now do veg versions. I've never quite done a yam version, but when I had left over thanksgiving in th past, I did layer meat, veg and top with sweet potatoes and gravy.