Add the chopped strawberries, caster sugar, lemon juice and salt to a medium saucepan and place it over a medium heat. Stir regularly and mash the strawberries as you stir to encourage them to release their juices.
Cook for 5 or so minutes or until the sugar has dissolved, the strawberries are softened and the mixture is bright red. Set aside to cool.
Give the strawberries one last mash with a fork to break them right down. Pour all of the mixture into your 470ml Ninja Swirl tub with the bottom mechanism closed.
Place the ice cream in the freezer for 24 hours with the lid off. Leaving the lid off while the mixture freezes can prevent it from forming a hump which can damage your machine.
When ready to eat, process the ice cream using the SCOOP and ice cream functions. The 'soft serve' functions processes cream based mixtures for too long which starts to split the cream.
If the mixture looks very soft, place it in the freezer for 30 minutes to firm up before continuing.
Swap the lids and attach the piping nozzle to your tub. Process into soft serve using the lever. If you get an error message, stop and allow the mixture to thaw for 5-10 minutes before proceeding.
There will be some slightly icy mixture leftover in the bottom of the tub as there with all soft serves made in the Swirl.