Step 1

In a large saucepan, melt the butter. Stir in the salt, sugar, water, and corn syrup, and bring the mixture to a boil. Boil gently over medium heat, WITHOUT stirring, until the mixture reaches hard-crack stage (300°F on an instant-read or candy thermometer). The syrup will bubble without seeming to change much for awhile, but be patient; all of a sudden it will darken, and at that point you need to take its temperature and see if it's ready. (If you don't have a thermometer, test a dollop in ice water; it should immediately harden to a brittleness sufficient that you'll be able to snap it in two, without any bending or softness). This whole process should take about 10 to 12 minutes. Pay close attention as it will go from ready to burnt if you aren't looking.

Step 2

While the sugar mixture is gently bubbling, spread half of the nuts, in a fairly closely packed, even single layer, on a parchment lined baking sheet (a half sheet pan works well). I made mine into a rectangle. It's not necessarily going to go to the edge of your pan just as big as you can make a rectangle with the nuts. Top with half the chocolate.

Step 3

When the syrup is ready, pour it quickly and evenly over the nuts and chocolate. Immediately top with the remaining chocolate, then the remaining nuts.

Step 4

Wait several minutes, then gently, using the back of a spatula, press down on the chocolate-nut layer and spread the chocolate around.

Step 5

When mixture has completely cooled, break or cut it into uneven chunks.

Step 6

Store cooled candy tightly wrapped; it'll stay fresh for a couple of weeks at room temperature. Freeze for longer storage.