To the jar of a blender add the chopped strawberries, sugar, lemon juice, cayenne pepper and salt. Blend until thoroughly pureed, about 1 minute.
Transfer the mixture to a tray. Cover with plastic wrap and transfer to the freezer.
At the 1 hour, stir the mixture, breaking up the icy bits. At the 2 hour, stir once more. At the 3 hour scrape the entire mixture using a fork until flaky crystals form. Cover tightly and freeze.
Store in the freezer until ready to serve. Just before serving, scrap it one more time.