Complex sentence: Lythgoe Family Productions has produced pantomimes each winter in California, starting with a production of "Cinderella" in 2010 starring Jerry Mathers and Freddie Stroma.
Split into simpler sentences: Lythgoe Family Productions has produced pantomimes each winter since 2010 in California. Their first production was "Cinderella", starring Jerry Mathers and Freddie Stroma.