Add the mango, almond milk and maple syrup into a blender and blend until smooth. Transfer into a small saucepan and bring to a gentle boil. Add in the agar agar, whisk well and boil with the lid on for an additional 3 minutes. Transfer to a bowl and set aside to cool.
In the meantime, add the aquafaba into a bowl and beat for 4-5 minutes until thick and fluffy. Add in the lemon juice and beat again for 1 more minute. Gradually add it into the mango mixture and gently fold through until well incorporated.
Divide into 4 serving glasses and place in the fridge to set for a minimum of 2 hours or simply chill overnight.
When ready to serve, top with fresh mango, mint and pistachio and enjoy.