Watermelon frozen yogurt

1. 1. Puree watermelon chunks in a blender or food processor. Strain out the grainy pulp and throw it away
2. Put watermelon juice back in the blender and add the yogurt, lime juice, and rum or vodka, and blend until its thoroughly mixed. Add sugar a little at a time. Taste and adjust as necessary.
3. Freeze the mixture in an ice cream machine. Enjoy as soft yogurt immediately or place in a freezer-safe container to achieve a hard freeze.
It keeps up to two weeks.