Add all ingredients to a high-speed blender. Blend until smooth, using the tamper if needed to help everything blend evenly. Add a little extra Greek yogurt only if necessary to get things moving.
Transfer the mixture to a freezer-safe container, smooth the top, and freeze for 4 hours, or until firm enough to scoop.
Let the ice cream sit at room temperature for a few minutes, or microwave for a few seconds, until soft enough to scoop.
Want it creamier and less icy? After freezing, break the ice cream into chunks and return them to the blender. Blend again until smooth and creamy. Serve immediately for a soft-serve consistency or refreeze. The ice cream will remain creamy after refreezing.