Idris Elba

According to an internet search, Idris Elba was an English actor, musician, voice actor and DJ. Tanya evidently admired him, as Ram Singh claimed that she would watch Downton Abbey if he was in it. (TV: For Tonight We Must Die)

Behind the scenes
His likeness was used in Sprout Boy meets a Galaxy of Stars, that featured the Twelfth Doctor, to portray character John Luther, the character was from a titular series Luther.