Combine all ingredients in a mason jar or other container that holds at least 12 ounces or 1 1/2 cups of liquid. Put the jar in the fridge at night.
In the morning, heat the oatmeal until warm. If you use a jar or other microwavable container, you can use that, or put it in a bowl. Then add nuts, additional fruit, raisins, yogurt, and any other toppings you like.
With coconut milk and blueberries, it is delicious to eat cold right out of the jar in the morning.