Cut avocados in half, remove pits and scoop flesh into a blender. Shake up the can of coconut milk before opening, and add to the blender. Add lime juice and agave nectar, and blend until smooth.
Test mixture for sweetness and add more agave nectar 1 teaspoon at a time, if desired. Don’t make ice cream base too sweet. Transfer base to an airtight container; place in the fridge and chill for at least 1 hour up to 4 hours. Pour mixture into a chilled canister of the ice cream maker; churn according manufacturer’s instructions. Serve ice cream immediately or place in an airtight container and keep in the freezer.