Which Cesar Award for best supporting actor winner starred in a movie that was in competition for the Palme d'Or at the 2008 Cannes Film Festival?
Jean-Paul Roussillon:  He won the César Award for Best Supporting Actor for his role in "A Christmas Tale". A Christmas Tale: A Christmas Tale (French: Un conte de Noël ) is a 2008 French comedy-drama film by Arnaud Desplechin, starring Catherine Deneuve, Jean-Paul Roussillon, Mathieu Amalric, Anne Consigny, Melvil Poupaud, Emmanuelle Devos and Chiara Mastroianni.
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