He speaks fluent Chinese and was Sveriges Television's first correspondent in Beijing between 2005 and 2008, and was their commentator there during the opening ceremony at the 2008 Summer Olympics.

Önnevall has presented the Sveriges Television shows Kinas mat and Fosterland, which also focused on China.

Önnevall studied journalism at Södra Vätterbygdens folkhögskola, and worked at Sydnytt as a reporter and editor in the late 1990s.

[3][4] He has made documentaries for Packat & klart, and along with Jacob Hård he provided commentary for the 2008 Summer Olympics opening ceremony.

[12] In late 2017, Önnevall presented the series "Bästa mannen", broadcast on Sveriges Television, where he travelled around Sweden interviewing men about how it is to be a man in today's society.