Roasted Sunchoke Mash

If you look at the photo above and exit this page, I understand. It's not very appetizing. But it's what food baked in a casserole dish, mashed together, usually looks like. So I'm not going to pretend otherwise.
So what is it? It's a roasted sunchoke, twice baked potato, onion, and garlic mash. It is winter comfort food.
I had a very bad experiences with sunchokes once. It was a few summers ago and we were eating at a fancy restaurant with a snooty waiter. Ew. And the only vegetarian item on the menu was a sunchoke puree with something (I can't remember what!) underneath. So I ordered it. And the puree came out half ice cold and half lukewarm. I asked the waiter about it and he was like, "it's supposed to be that way."
What? Since when did restaurants serve a food that was half ice cold and half warm? Like I get it if it was hamburger (warm patty, cold lettuce, etc) or a pasta salad (warm-ish pasta with cold avocado)
But not a puree. I asked the waiter to rewarm it, please. He wasn't too happy. And I decidedly hated sunchokes.
So how did I come into possession of a bag of sunchokes? They were cheap at the store.
I did a lot of research on sunchokes last night. Just their name is disturbing. They are also called jerusalem artichokes or in Swedish "jordärtskocka." In my research I couldn't find anything terribly wrong with them: i.e. nothing about people choking. However, supposedly some people can't handle the carbohydrates in them and they can cause terrible stomach pains, but the majority of people have no problems. Dinner in our household is always an adventurous risk!
Last night was the Great Sunchoke Experiment and it was successful. They're good you guys! Especially served at the same temperature throughout. They're kind of nutty and earthy.

Winter Mash: Roasted Sunchokes, Potatoes, Onions, and Garlic
4-5 sunchokes
3 medium sized potatoes*
1 large yellow onion
4-6 garlic cloves
Olive oil to drizzle
Salt and Pepper
Oregano
Parmesan cheese for grating
Fresh spinach

Preheat your oven to 200c. Wash and peel the sunchokes. Slice into medium-thin discs (as you would with potato gratin). Wash and peel your potatoes, slice into medium-thin discs like the sunchokes. Chop your onion into long, thin slices. Remove the papery skin from the garlic cloves and chop each clove in half. Throw everything into an oven proof baking dish. Drizzle with olive oil, sprinkle with salt, pepper, and oregano. Mix together. Bake for about 30-40 minutes until all can be pierced with a fork.
When out of the oven, grate a fine sprinkling of parmesan cheese over the mash. Serve in a bowl on a fresh bed of spinach.
It's good!

Notes:
* We had three potatoes that were already baked sitting our fridge so I used those instead of starting with raw potatoes. I put them into the mash about halfway through the baking times for twice-baked potatoes a la Central Market.