Complex sentence: In addition to producing a large body of work, Mitchell served as professor of creative writing and writer-in-residence at several Canadian universities and was the director of the Banff Centre's writing division.
Split into simpler sentences: In addition to producing a large body of work, Mitchell spent a great deal of time teaching others the craft of writing. He served as professor of creative writing and writer-in-residence at several Canadian universities and was the director of the Banff Centre's writing division.