Rinse the Arborio rice under cold water until the water runs clear to remove excess starch.
In a medium saucepan, combine the rinsed rice, coconut milk, water, sugar, and salt. Stir well to dissolve the sugar.
Place the saucepan over medium heat and bring the mixture to a gentle boil.
Reduce the heat to low and simmer, stirring occasionally, for about 20-25 minutes, until the rice is tender and the mixture has thickened to a creamy consistency.
Stir in the vanilla extract and ground cardamom, and cook for an additional 2-3 minutes. Remove from heat.
Allow the pudding to cool slightly, then fold in the diced mango gently, reserving some for topping.
Serve warm or chilled in individual bowls, and top with additional mango, toasted shredded coconut, and fresh mint leaves for garnish.
Notes
Serve warm or chilled, garnished with additional mango and mint.