Make the Mango “Milk”: Add the mango to a high-speed blender along with the milk, water, lime juice, maple syrup, vanilla, and salt. Blend on high for 45 to 60 seconds, until everything is smooth; the mixture may look thick, but this is ok!
Mix: Add the oats and chia seeds to a large bowl and mix well. Pour the mango milk into the bowl, then add the chopped mango and stir until everything is combined. Let sit for at least 5 minutes, to allow the oats and chia seeds to absorb some of the liquid. Then, mix again to incorporate the extra liquid sitting on top.
Store & Serve: Transfer the oatmeal to jars or other containers, then store in the fridge for at least 4 hours, preferably overnight. Top as desired and enjoy cold or warm; leftovers will keep in the fridge for up to 5 days.
Non-dairy Milk: I recommend using a thick and creamy milk, like cashew, oat, or soy milk.
Protein Powder: For a protein boost, add 1 scoop of vanilla protein powder to the mango milk ingredients. Add an additional 2 tablespoons of plant milk and omit the sweetener if your powder is sweetened.