Question: For which opera was the teacher of Der Bärenhäuter best known?
Context: Eli Jaxon-Bear (born Elliot J. Zeldow in 1947) is an American spiritual teacher and author.  He lives in Ashland, Oregon with his wife, fellow spiritual teacher Gangaji.  Before he met his teacher, Sri H.W.L. Poonja, in 1990, he was best known for his work on the spiritual dimension of the Enneagram.  Following his meeting with Poonjaji he continued to teach, carrying his teacher’s message to the West. Hervey Alan (22 February 1910 – 12 January 1982) was an English operatic bass and voice teacher.  During his career he sang leading roles with most of Great Britain's major opera institutions, including the Edinburgh Festival, the Glyndebourne Festival, the Royal Opera House, the Sadler's Wells Opera, and the Welsh National Opera.  He is best known for creating the role of Mr. Redburn in the world premiere of Benjamin Britten's "Billy Budd" at the Royal Opera House, London, on 1 December 1951.  Music critic Elizabeth Forbes wrote that his voice was "dark toned, resonant", and "especially effective as Zaccaria in "Nabucco". Jan Gabriël Van der Watt (born 5 November 1952) is a South African biblical scholar and Bible translator who moved to the Netherlands in 2009 to take up a chair in New Testament and Source texts of early Christianity at Radboud University in Nijmegen.  For a quarter of a century previously, he was professor at the University of Pretoria, where he was named as one of the 100 most influential academic thinkers in the 100-year history of the University of Pretoria, South Africa (see www.up.ac.za under Leading Minds).  Van der Watt was also rated as international acknowledged researcher that is regarded by some of his international peers as international leader in his field, (see www.nrf.ac.za under rated researchers).  Van der Watt is internationally best known for his monograph: Family of the King: Dynamics of Metaphor in the Gosepl According to John. Petrus Andreas Maria (Peter) Bos (born 20 June 1950 in Amsterdam) is a Dutch film, stage and television actor best known for his role in the 1982 children's television series "De Zevensprong" in which he played the leading part as the teacher Frans van der Steg.  He is also known from the children's film "Knokken voor twee" (directed by Karst van der Meulen) which was released in the same year. Engelbert Humperdinck (] ; 1 September 1854 – 27 September 1921) was a German composer, best known for his opera "Hansel and Gretel". Der Bärenhäuter is an 1899 German-language opera by Siegfried Wagner based on the German folk tale Der Bärenhäuter, or the Bearskin man.  As with most of Siegfried Wagner's operas it is more influenced by his teacher Humperdinck than his father Richard Wagner's operas. Christopher Larkin is an American conductor who is best known for his work within the field of opera.  He was Associate Conductor of the Houston Grand Opera for a number of years where he notably conducted the world premieres of Mark Adamo's "Little Women" and Michael Daugherty’s "Jackie O".  He is also the former Music Director of the New York City Opera National Company.  As a guest conductor, Larkin has worked for numerous opera houses including Wexford Festival Opera, Santa Fe Opera, Washington National Opera, Portland Opera, Florentine Opera, Opera Pacific, Opera Carolina, and Boston Lyric Opera among many others.  He has also worked as an Assistant Conductor and vocal coach for the Metropolitan Opera, San Francisco Opera, Opera Company of Philadelphia, Vancouver Opera, and the Canadian Opera Company. Rick van der Linden (5 August 1946, Badhoevedorp, North Holland - 22 January 2006, Groningen) was a Dutch composer and keyboardist.  Van der Linden first gained fame as a member of Ekseption, but he played in several other bands including most notably Trace, as well as solo.  Van der Linden was best known for his reworkings of classical music in a pop music domain, often with jazz improvisations. "Nun komm, der Heiden Heiland " (original: "Nu kom der Heyden heyland ", English: "Now come, Saviour of the heathens") is a Lutheran chorale of 1524 with words written by Martin Luther, based on "Veni redemptor gentium " by Ambrose.  It was printed in the Erfurt "Enchiridion" of 1524.  The chorale was used as the prominent hymn for the first Sunday of Advent for centuries.  It was used widely in organ settings by Protestant baroque composers, most notably Johann Sebastian Bach: he set it as the opening chorale prelude BWV 599 of Orgelbüchlein; and three times—as BWV 659 (one of his best known organ compositions), BWV 660 and BWV 661—in his Great Eighteen Chorale Preludes.  Bach used the hymn in his chorale cantata "Nun komm, der Heiden Heiland", BWV 62 (1724) and in the opening chorale fantasia of his earlier cantata "Nun komm, der Heiden Heiland", BWV 61 , BWV 61 (1714).  Max Reger composed a chorale prelude as No. 29 of his 52 Chorale Preludes, Op. 67 in 1902. Derek Hammond-Stroud, OBE (10 January 192614 May 2012) was an English baritone opera singer best known for his performances of German lieder and his international performances in opera, particularly the roles of Alberich in Wagner's "Der Ring des Nibelungen", Herr Faninal in "Der Rosenkavalier" and Beckmesser in "Die Meistersinger von Nürnberg".  He also made recordings, including a series of recordings of the Gilbert and Sullivan patter roles.
Answer: Hansel and Gretel