Pattern Recognition. Crowborough Rapid Play Rd 5

I play anti-sicilian lines against 1....c5 because I hope to get my opponent out of his book and into mine.  Some think these lines are dull. 

Often, White trades his bishop for a knight and in return gets a lead in development.  If black is not careful it is possible to use this edge to whip up a potent attack on the king side.

Having knowledge of characteristic positions from a wide variety of openings enables strong players to recognise positional patterns.  In this game the  early middlegame resembles a king indian attack with white having lodged a pawn on e5.

Later on there is a very thematic sacrifice.  Again, I did not have sufficient time or ability to calculate all the lines - but I recognised the pattern and that gave me the confidence that it was playable.

A quick problem - white to play  can you find the shocking move that enables an easy win ?