Firstly melt the pistachio butter so it can easily be incorporated into the milk. You can do this in a small saucepan on the stovetop, or in the microwave for a few seconds.
Once the pistachio butter is slightly runny, whisk in about 3 tbsp of the milk until it is all combined.
Add the pistachio milk to a mason jar along with the rest of the milk and the remaining ingredients. Stir everything well to combine.
Screw the lid onto the jar and refrigerate overnight.
The next morning, stir the oats before enjoying hot or cold alongside your favourite toppings! I like raspberries, chopped pistachios, white chocolate and rose petals.
Notes
*You can also use pistachio cream instead of pistachio butter. If so, then omit the honey to avoid the oats becoming too sweet.
Prepared overnight oats will last in an airtight container in the fridge for up to 3 days.