Ok this is my "go to" staple. I have made it for friends, and for groups. If you happen to undercook it (by eyeballing the color) it will end up softer, and slightly grainy. However either way, it is awesome!
2 cups butter (please do not use margarine!)
2 cups white sugar
1/4 tsp salt
2 cups chocolate chips (I use milk chocolate just as preference, any chocolate would be good!)
1 cup finely chopped almonds.(optional)
In a large heavy bottomed saucepan, combine butter, sugar and salt. Cook over medium heat (this is REALLY important!) , stirring until the butter is melted. Allow to come to a boil and cool until the mixture becomes a dark amber color, and the temperature has reached 285 degrees. Stir occasionally.
While the toffee is cooking, cover a large baking sheetwith aluminum foil or parchment paper (I prefer the parchment paper)
As soon as the toffee reaches the proper temperature, pour it out on to the prepped backing sheet. Sprinkle the chocolate into a thin even layer once it has melted. Sprinkle the nuts over the chocolate and press slightly. Putting a plastic a bag over your hand will minimize the mess.
Place the toffee the refrigerator to chill until set. Break into pieces and store in an air tight container.