The idea is to layer the ingredients in a glass, with the almond milk and chia layering together so the chia soaks up the milk and swells into a gel-like substance. Add 1 tablespoon chia and a third of the milk. Then add 1 tablespoon coconut flakes, a third of the mango and repeat. Alternatively, you can just throw all the ingredients together in a bowl.
Cover the glass or bowl with glad wrap and refrigerate overnight, or at least 3 hours.