You're going to have to light for it. Which, if it were me, would mean using a grid spot to light the area above the bowl so that the steam is illuminated. You're going to want a fast shutter speed. Since steam appears white, it would work better against a dark background.
Oh bummer. I have the dark background. You all would laugh if you saw what kind of lights I use. It's kinda sad... but it is all I have. I will try get one of them above see if that would work....