125ml (4 1/2 fl oz) cold milk
1 tablespoon vanilla essence
1 (405g) tin sweetened condensed milk
1/8 teaspoon salt
475ml (16 fl oz) double cream
1.       In a medium bowl, stir together cold milk, vanilla, condensed milk and salt. Set aside.
2.       In a large bowl, beat double cream with an electric mixer until stiff peaks form. Fold milk mixture into whipped cream.
3.       Pour into shallow 2 litre dish, cover and freeze for 4 hours, stirring once after 2 hours or when edges start to harden. Serve or store in an airtight container up to 10 days.