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.
Taste test before placing in machine, so you'll have an idea if the recipe needs more lime or sugar to suit your taste. I often substitute half and half for 2% milk or vanilla soy milk. I have even used canned evaporated milk (chilled) - NOT the non-fat version. The less fat, of course, the more icy the resulting product will be. Lemon would probably work equally well, in place of lime.
Per Serving: 371 calories;24.5 g fat;
40.4 g carbohydrates;
3.2 g protein;
11 mg cholesterol;
26 mg sodium.