In a saucepan boil the sugar and water together to make a caramel. Test the color of the caramel on a white plate. It should be amber-brown. Stir in the butter with a wooden spoon then stir in the nuts. Pour onto a silpat and let cool. Break up into chunks (for brittle, just chop or crush with the bottom of a bottle). Store in an airtight container.
Recipe courtesy of Gale Gand