just play bxc5, let him take your queen, and you take his.

If I'm playing Black, and it's my move, I'm taking your queen, which just about restores the material balance, although you now have choice between taking the Na3 or the Bc5. After this, the only specific tactic I see is for Black - he has the potential to win the exchange after ...Nxf2+, Rxf2 Qxf2 (otherwise he can get a smothered mate by Kg1 Nh3+, Kh1 Qg1+, Rxg1 Nf2#. This tactic would show itself after 1...Nxa3, 2.bxc5 Qxc5, 3.Nxa3 Nxf2+. And if you try 3.h3 Nc2, 4.hxg4 Nxa1 Black may be better. Going back to the diagram, there is also 1...Nxa3, 2.Nxa3 Bxf2 (still angling for the smother mate by 3...Bg1 and 4...Nf2+), 3.h3 and maybe you hang on to your extra piece. But hold on, there is also 1...Nxa3, 2.Nxa3 Nxf2+, 3.Kg1 Nh3+, 4.Kh1 Nf2+ when you can choose between giving back an exchange or a draw by perpetual check. So, I guess I'm not convinced White is winning here. I did not pull out a board and really analyze deeply, but this is my impression. For White to win, if he keeps the extra piece, the general strategy would be to trade all the pieces since you are up a piece. That gets you an endgame where you have a piece and Black doesn't. Easy pickin's. But if White can't hold the extra piece Black is still in the game. Just one opinion...