To prepare the mango. Ignore instructions that tell you to peel a mango before slicing. That is a very sticky, slippery job.
Stand the mango upright with the pointed end up, slice down either side of the flat inner stone to get two pieces like small shoulder pads.
Using a sharp knife and mango skin down on chopping board not in your hand, carefully cut through the flesh to the skin in a ‘tic tac toe’ pattern. Press the middle of the skin one direction while pushing the edges in the opposite direction.(turning inside out). This makes the mango pieces stand individually upright so you can cut them off the skin with a sharp knife.
Return to the semi-peeled mango and follow the curve of the stone to cut off the remaining skin/flesh in 2 pieces. Cut these pieces away from skin.