In a medium saucepan, bring the half-and-half, sugar and lime peel to a boil, stirring often, over medium-high heat. Let cool for 2 minutes. Strain the mixture into a bowl and discard the peel; rinse and dry the saucepan.
In the saucepan, combine the half-and-half mixture with the coconut milk and tapioca; let stand for 10 minutes. Whisk in the egg and ginger and bring to a boil, whisking constantly, over medium-low heat. Remove from the heat and stir in the vanilla. Transfer to a medium bowl. Press plastic wrap onto the surface of the pudding to prevent a skin from forming; let cool to room temperature, then refrigerate until chilled. Serve with the mango.