How to Make It
In a medium saucepan, combine the milk and sugar and bring to a simmer over moderate heat. Stir well to thoroughly dissolve the sugar. Add the tapioca and the vanilla bean and simmer over low heat, stirring often, until the tapioca is tender but still slightly chewy, about 1 hour.
Pour the tapioca pudding through a coarse sieve set over a large bowl. Scrape in the seeds from the vanilla bean; discard the bean. Stir in 1/3 cup of the milk in which the tapioca was cooked, then add the coconut milk. Cover and refrigerate until the pudding is cold and thickened, about 3 hours.
In a medium glass or ceramic bowl, gently stir together the diced papaya, pineapple, cantaloupe and mango.
To serve, spoon the pudding into 4 small bowls and top with the diced fruit. Alternatively, layer the tapioca pudding and the diced fruit in parfait glasses. Serve the pudding at once or refrigerate for up to 2 hours.