How to Make It
In a medium enameled cast-iron casserole, combine the milk with the rice, coconut milk, vanilla bean and seeds and the poppy seeds and bring to a simmer over moderately high heat, stirring. Reduce the heat to low and simmer, stirring often, until the rice is tender, about 1 hour and 20 minutes.
Stir the sugar, heavy cream and lime zest into the rice and simmer, stirring occasionally, until the rice pudding is sweet and fragrant, about 10 minutes. Let cool to room temperature, then cover tightly and refrigerate until chilled, about 2 hours. Spoon the rice pudding into small bowls and top with the mango.