In this article the writer suggests slightly caramelizing table sugar and after that toss the onions in the caramelized sugar. My question is - wouldn't you need a fat like butter to transfer heat from the pan to the onions? Does he take for granted we add butter to the caramel? Or does he mean we add sweated onions to the caramel together with the fat?
You do not add fat to sugar when caramelizing it, you add it to the pan dry. Sugar has water suspended in it, and it comes out when heated. The caramel will transfer the heat to the onions just fine - anyone who's ever gotten splattered with hot caramel will attest to that.