In a medium bowl, mix the milk, sugar, and vanilla. Once the sugar has dissolved, stir.
If using an ice cream maker, add the milk mixture and process for 20 minutes, or until the liquid thickens. Pour contents into Tupperware and freeze for eight or more hours. Stirring approximately every 4 hours until completely frozen may help the consistency.
If not using an ice cream maker, pour into a shallow dish that is freezer-proof and place in the freezer. After crystals have formed, stir every 2-4 hours. For freezing, follow the steps above.