Add all ingredients to a high speed blender and blend until smooth.
It will likely take a couple runs to grind all the chia seeds fully.
Serve with (plenty!) whipped cream and sprinkled with peppermint 'sugar'.
NOTE: Be VERY careful when opening a high speed blender with a hot liquid, as it may create a vacuum.
And if using a NutriBullet or similar device, keep in mind that you should not put scalding hot water in it.
Keep it warm and blend it only for 10 seconds at a time, allowing the pressure to release every time.
If need be, reheat (safety comes first!).