Whisk coconut milk, sugar, half-and-half, lime juice, lime zest, and salt together in a bowl until sugar dissolves. Transfer coconut mixture into an ice cream maker and freeze according to manufacturer's directions until it reaches 'soft-serve' consistency.
Transfer ice cream to a lidded plastic container; cover surface with plastic wrap and seal. For best results, ice cream should ripen in the freezer for at least 3 hours or overnight.
Scoop ice cream into stemmed glasses or bowls. Garnish with mango and and lime slices.
