Thanks for your answer!
Hmm as far as I understand it, the tesselator doesn't draw anything at all. Maybe I'm off here but it seems to me that one provides callback methods (or as we're in the java world, a callback object) which get called when the tesselator runs. My idea was therefore to let the tesselator do its magic, collect the result through the callback methods (beginData, vertexData, endData) and store this into a vertex buffer for later rendering. Maybe I understood that wrong, but to me the idea seems to be that one can pretty much run any code in the callback, so why not "generate" tesselated polygons for later use?
As for ear clipping and monotone polygons: I would prefer not having to implement this on my own because I would like to focus on other aspects than the tesselation itself.