Spread out the walnuts on a baking sheet and toast in the oven at 200 C/ 400 F / gas mark 6 for about 5 minutes until browned. Tip into a wire sieve and shake off all the loosened, papery skin. Cool and chop roughly.

Heat the maple syrup to boiling point. Meanwhile, whisk the egg white with the salt until it forms soft peaks. Gradually pour in the very hot syrup, whisking constantly. Continue whisking until you have a thick, stiff meringue. Use an electric whisk if you have one. Leave to cool.

Beat the cream until stiff, then fold into the maple meringue. Finally fold in the nuts. Spoon into a dish and freeze. Transfer to the fridge to soften for half an hour before serving.

walnuts go very well together, though you could substitute pecan nuts.