Dice the raw chicken, spray the pan with PAM and cook until tender, remove from heat.
Dice in big chunks the onion, mushrooms, and peppers and toss in the wok or large frying pan on medium high heat until cooked.
In a separate saucepan, crush garlic and add sliced mangoes, lime juice, fish sauce, soy sauce, chili flakes and brown sugar. Simmer and stir on low heat until flavors meld.