Preparation - In a large saucepan, combine the sugar, water, and corn syrup. Cook over medium-low heat until the sugar is dissolved. Stir in the butter and bring to a gentle boil over medium heat, stirring constantly. Cook and stir until a candy thermometer reads 280º. Stir in the nuts and continue to cook until a candy thermometer reaches 300º. Remove from heat and quickly stir in the baking soda. Pour the mixture onto a large buttered cookie sheet. Use a spatula to stretch and spread a thin a thin layer over the pan. Let the mixture harden for a few minutes, then remove from the pan and break into pieces with the handle of a heavy table knife or with a small, clean hammer. Store in an airtight container at room temperature.
