Jerusalem artichokes

We have Jerusalem artichokes in our garden. Not to be confused with the other type of artichokes, they aren't really artichokes at all, but tubers - they are like little potatoes, but knobbly and gnarly and sweeter and smokier.. they look like this:


They are yummy when roasted or fried, but the other day I made a soup, which Matt enjoyed very much.. basically I cooked them with butter and onions and stock and pepper, then pureed it all and got this.......



Also, they make you fart. Lots.