In a large saucepan over medium high heat, combine cream, milk, erythritol, cocoa powder, arrowroot starch and salt. Whisk until smooth and continue to whisk frequently until mixture boils.
Boil one minute, and then remove from heat.
Add chopped chocolate and let sit 2 minutes, until chocolate is melted. Whisk in chocolate until smooth.
Transfer mixture to a medium bowl set over an ice bath and let cool 10 minutes. Cover tightly with plastic wrap and refrigerate until completely chilled, at least 3 hours.
When chilled, stir in vanilla and stevia extracts. Sprinkle with xanthan gum and whisk briskly to combine.
Pour mixture into the canister of an ice cream maker and churn according to manufacturer's directions. Once churned, transfer to an airtight container and press plastic wrap flush to the surface. Freeze 1 hour or until firm but not rock hard.
Serves 6. Each serving has 9.3 g of carbs and 2.3 g of fiber. Total NET CARBS = 7 g.