If by "decent" you mean professional, then I've no idea. Kamienica Theater was planning on staging a cabaret-type play for English-speaking audiences, but as far as I know the idea died.
There is an amateur theatre called The Cheerful Hamlets, they perform in English. Their website sucks big time as the latest info you can find there is from 2003, but I know they still perform (last year they were staging Shaffer's Black Comedy and Hamilton's The Rope, just to give you an idea of the kind of plays they do).
