Cut watermelon into small chunks, removing both the outer rind and black seeds (if there are any).
Freeze the watermelon chunks for at least 4-5 hours, until fully frozen.
Making the ice cream
Add the watermelon chunks to a food processor with half of the coconut milk. Process the mixture until smooth, adding in the rest of the coconut milk, as needed, to help the process go more smoothly, and to make a creamier watermelon ice cream.
Scoop the watermelon ice cream into bowls for serving immediately. If you want to make a more solid ice cream, store in the freezer for more time, as needed.
Homemade coconut milk can be used in this recipe. The coconut milk can also be substituted with coconut cream or another milk or cream. This ice cream is best made immediately before serving. Once you have the watermelon cubes frozen, it can be made in just a few minutes. If the ice cream is too soft, place it in the freezer, stirring occasionally, until you are happy with the consistency. I find this ice cream sweet enough on its own, but you can optionally sweeten it with stevia, maple syrup, or another sweetener. To sweeten it with a simple sugar syrup, make one by cooking equal parts of sugar and water over low to medium heat until the sugar has dissolved. Once cool, add the syrup to the food processor with the other ingredients.Leftover ice cream can be stored in the freezer, but it will become quite hard. To serve, remove from the freezer to soften it before serving. For best results, soften it by thawing it in the fridge. You can also reprocess the hard ice cream in a food processor to get the perfect consistency. (This is best done by freezing it in ice cube trays.) Similar ice creams can be made with other fruits. Pineapple ice cream is delicious!