Combine whole milk, heavy cream, vanilla, peppermint oil, sugar, and salt in a large bowl.
Stir until sugar is dissolved, about 3-5 minutes.
Pour mixture into ice cream machine and freeze according to the packaging instructions.
Once at soft-serve consistency, transfer into a large bowl and stir in crushed peppermint.
Transfer into a freezer safe container and freeze for 1 hour, or until hardened.
Notes
Substituions:
You can use half and half instead of whole milk.
Peppermint Schnapps or something along those lines can be used to substitute the peppermint oil. You will need to adjust the amount depending on the strength of flavor.
Expert Tips:
When mixing the base for the ice cream, be careful when stirring! You don't want to beat it.