Melt the chopped chocolate, condensed milk and salt in a heavy based pan on a low heat.
Put the nuts into a freezer bag and bash them with a rolling pin, until broken up into both big and little pieces.
Add the nuts to the melted chocolate and condensed milk and stir well to mix.
Pour this mixture into a 9-inch square foil tray, smoothing the top.
Let the fudge cool and then refrigerate until set. You can then cut into small pieces approximately 3/4 by 1 3/4 inches or cutting 8 by 8 lines in the tin to give 64 pieces.
Once cut you can keep it in the freezer, no need to thaw just eat straight away.