Peel the mango and slice the flesh off the stone. Discard the stone. Peel the lemon and halve it. Flick out any pips.
Add the mango and lemon flesh to a blender. Add a small pinch of cayenne – the cayenne is very spicy, so just add a little pinch to start with. Pour in 330ml almond milk.
Add a handful of ice cubes. Blend till smooth and creamy. Taste and add a pinch more cayenne if you think it needs it. Pour into glasses and serve.