Complex sentence: The following year, Wertmüller made her directorial debut with "The Lizards" ("I Basilischi"), a film whose subject matter (the lives of impoverished people in southern Italy) would become a recurring motif in her later work.
Split into simpler sentences: The following year, Wertmüller made her directorial debut with "The Lizards" ("I Basilischi"). The film's subject matter--the lives of impoverished people in southern Italy--became a recurring motif in her later work.