Channing-Williams first began working with Leigh as an assistant director on the 1980 BBC film "Grown Ups", and moved to producing with Leigh's featurette "The Short and Curlies" (1981). Since then, he co-produced Leigh's "High Hopes" (1988), about a working-class couple. Soon after, they formed Thin Man Films which has offered "Life Is Sweet" (1991), "Naked" (1993), and also Tim Sullivan's "Jack & Sarah" (1995).
Channing-Williams began his career in production, working as an assistant director on numerous films and TV projects. As late as 1984, he was Hugh Hudson's assistant director on "Greystoke: The Legend of Tarzan, Lord of the Apes". He moved into associate producing after that, working in that capacity on the TV-movies "Wagner" and "Puccini". He became a full-fledged solo producer with Clive Rees' "When the Whales Come" (1989). In addition to projects with Leigh, Channing-Williams has produced "The Great Kandinsky" for the BBC, (seen in the USA on PBS' "Masterpiece Theatre" in 1995). But "Secrets & Lies" has become his and Leigh's most celebrated project to date, being named Best Picture by the Los Angeles Film Critics Association and earning five Oscar nominations, including Best Picture.