Mango: Slice the mango lengthwise along the pit. Scoop out the flesh from both halves and set it aside for blending. Cut off any remaining flesh from around the pit, dice it into small pieces, and save it for topping your oats later.
Blend: Add the mango flesh, plant-based milk, lime juice, and vanilla extract to a blender. Place a fine-mesh sieve over the blender jug, then scoop the passion fruit pulp into the sieve. Use a spoon to press the juice through while leaving the seeds behind. Discard the seeds, then blend everything until smooth and creamy.
Dry ingredients: Add the rolled oats, quick-cooking oats (if using), chia seeds, and salt to individual jars.
Combine: Divide the mango mixture evenly over the jars with dry ingredients. Stir each jar well to make sure everything is fully combined and no oats or chia seeds are stuck at the bottom.
Meal prep: Top with the reserved mango pieces. Seal the jars with lids and place them in the fridge overnight. These will keep well in the fridge for up to 4 days.