Mix together all the ingredients in a jar or bowl.
Cover and refrigerate for at least 4 hours (ideally overnight).
When ready to eat, give everything a good stir. If it's too thick, add a little more milk or yogurt. Enjoy!
Notes
Apples: Feel free to stew the apples for minutes to get rid of their raw taste! Just throw them in a saucepan with 1 tablespoon of water. Bring to a boil, then cover, reduce to the lowest setting, and cook for 5 minutes.