For the melon buttermilk dessert, cut the watermelon into cubes, season with cinnamon and sugar or sweetener and mix with the buttermilk.
Soak the gelatine in a little cold water (about 4 minutes), then drain the water and heat the wet gelatine sheets until they dissolve (it’s quite quick).
Mix a tablespoon of the buttermilk with the gelatin and stir until smooth, then stir the gelatin into the watermelon buttermilk.
Allow to set in the refrigerator for about 4 hours.