Complex sentence: After Norman's move back to California the technique was used to create a mural at Casa Munras Hospital in Monterey and it was this which attracted the Masonic Temple's architect Albert Roller.
Split into simpler sentences: After Norman's move back to California, the technique was used to create a mural at Casa Munras Hospital in Monterey, California. It was this mural which attracted the attention of the Masonic Temple's architect Albert Roller.