Seasoning le creuset?
It's coated with enamel, so seasoning is not necessary (or feasible, for that matter). They're oven safe to about 350 degrees. I like to wrap the handle with a little foil as a protective measure. If you want to use it at higher temperatures, find a nice looking metal handle that's about the same size (your friendly local hardware store carries drawer pulls that work brilliantly) and replace the plastic handle. All you'll need is a screwdriver.