Do you want to know something weird? The guy from the Grey Poupon commercials isn't British! Like, in your head, the jaunty fellow whole rolls down his window and says, "Pardon me? Would you have any Grey Poupon?" has a British accent, right? Wrong! Your head is wrong! He was American the whole time!
Jame Bond's boss, M, however, is very, very British. Really, he is exceedingly, incredibly British. As this delightful Adult Swim video just barely manages to point out.