Sunday Chess Puzzle, November 28

Today's chess puzzle is a tactic that I missed in a game this week. White to play.

I, as black, had lost material early on, and had committed to a slightly premature attack on the white king to compensate for it. At this point, white appears to be in a perlious position with her king under attack from three strong pieces. Although white is completely winning here (if white plays gxh3, diffusing black's attack), white played Bxc6??, which loses the game. After white plays Bxc6, how should should black continue her attack?