Finely grate zest from lime and squeeze juice into a medium saucepan.
Place the cream layer from the canned coconut cream in a mixing bowl and whip until stiff peaks form.
Pour the liquid part of the coconut cream into a saucepan with lemon juice.
Stir in sweetener, blueberries, and low-carb milk.
Heat to boiling then cook, stirring occasionally, on gentle boil about 4 minutes.
Remove from heat and whisk in xanthan gum, if using. Allow to cool a bit, then fold in whipped coconut cream.
Place mixture in refrigerator or ice bath until well chilled.
Process in ice cream maker according to manufacturer's directions.
Notes
Use a blended sugar substitute. I like to use a powdered blend of monk fruit and allulose.Churn the cream mixture in an ice cream maker. This is a sugar free churn ice cream. However, it is possible to make ice cream in a food processor. But I haven't tried this recipe using the food processor method.Don't skimp on fat. Ice cream high in fat has a creamier consistency so you can use more high fat cream and less milk.Mix in some unsweetened shredded coconut if you want more coconut flavor.