On an un-sprayed cookie sheet, spread 1/3 C ground nuts and finely shredded chocolate. (sprinkle evenly)

In a heavy 4 quart pan on medium heat melt butter, add sugar, water, karo.

Insert candy thermometer and turn up the heat to medium high cook to 300 degrees, hard crack (280 for high elevations). Stirring constantly with a wooden spoon. Pour quickly onto cookie sheet.

Separate remaining chocolate into squares and set on toffee, when it starts to melt push the chocolate around with a knife until completely melted, and spread evenly over toffee.

Top with remaining nuts.

Cool for 2 hours in a cool place. Break into pieces and serve.