Puree the fruit in a blender until smooth, add up to 1/4 cup water if needed to thin.

Add the vodka to the mixture and taste for acidity, add lime juice if necessary.

Stir in the sugar (or agave nectar) until dissolved, starting with 1/2 cup and adding more as needed (starting with 1/3 cup if using agave).

Freeze in an ice cream maker until thickened (about 20-30 minutes).

Transfer to the freezer and let firm up before serving.