Freeze the bananas and strawberries as needed, at least a day ahead of making this. Then measure out all your ingredients.
Place all ingredients in a blender or food processor.
Blend until smooth. You may have to stop it, remove the lid, and poke around at everything a few times to get it all blended properly. If the mixture seems too dry to process properly, add a small splash or two of milk to get things loosened up enough to blend. Then start it again. Add more as needed to avoid burning out your motor.
Depending on how frozen your fruit is or how much liquid you added, it may be necessary to spread out the ice cream over a shallow dish and freeze it for an hour or two before eating.
Serve in your favorite ice cream dish and enjoy!
Notes
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.