Peel the avocado, remove the stone and mash the pulp with a fork. Mix the pulp with half a teaspoon of finely grated lime zest and two to three teaspoons of lime juice. Finely dice the chilli pepper and onion. Dice the flesh of the mango (peeled and pitted) a little coarser. Mix everything into the avocado mixture and season with salt, pepper and possibly a little agave syrup.
Finally, garnish the guacamole with diced mango and mint.