Answer
The first original West End stage musical directed by Sam Mendes is Charlie and the Chocolate Factory, a theatrical adaptation of Roald Dahl's beloved children's novel, which premiered in 2013. This captivating musical journey takes audiences into a whimsical world filled with colorful characters, memorable songs, and magical surprises, as young Charlie Bucket embarks on an extraordinary adventure within the enigmatic chocolate factory of Willy Wonka.