Melt the chopped chocolate, condensed milk, butter 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 23cm square foil tray, smoothing the top.
Let the fudge cool and then refrigerate until set. You can then cut into small pieces approximately 2 by 4cm 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.
Recipe from Nigella Express by Nigella Lawson (published by Chatto & Windus)
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