Wash chicken and dice. Mix with marinade. Leave in a cool place for at least 30 minutes. Can be left in the fridge for 2 hours to overnight for deeper favour.
Cashew nuts - if you have some nice crispy bought nuts (not honey roasted which will be too sweet for the dish), you can save time by using them instead of preparing the nuts according to steps 2 & 3. Bring 100 ml of water to the boil. Add ¼ teaspoon of salt and ½ teaspoon of brown sugar (more favour and also a bit of salt will make the nuts more crispy after deep fried / baking). Put in cashew nuts and simmer for 30 minutes (so the salt and sugar not only coat the nuts but deposit inside). Remove and drain.
Pre-heat an oven (160C for fan-assistant oven, I am not sure the temperature for those without fan, may be 170C). Use an oil brush to grease a baking plate. Put in a teaspoon of oil (oil/butter, though it seems that butter gives a better favour and texture). Pour in the cashew nuts. Keep an eye on the nuts, once there is no more water bubbles evaporates (takes about 30-45 minutes, the nuts would not be crispy with any moisture inside), uses the oil brush to brush all over the nuts. Bake for another 15 minutes or when the nuts become light brown (the colour will become darker when cool). Pour over a piece of kitchen paper on a rack to cool. (It is essential to coat a layer of oil so the nuts can remain crispy much longer after mixing with the sauce. Some people may prefer deep-fry but too much oil is needed while my husband needs to loss weight. You can double the amount and leave half in an air-tight jar for next meal but I don't do it myself as my husband will finish it quickly.).
Heat a non-stick wok with medium heat and add a tablespoon of oil (2 tablespoons of oil if you use a normal wok). Put in garlic and chilly pepper. Stir fry for a while till you can smell the garlic.
Add chicken and stir fry till it is done. Take out the chicken and put aside. (Don’t worry if the marinade sticks to a normal wok, as the pineapple juice we use later will solve the problem.).
Put in green pepper, stir fry for 1 – 2 minutess (depending on the hardness of the pepper).
Put back the chicken and add the red pepper and stir fry. Pour in seasoning and stir fry until the sauce reduces.
Add the pineapple and mix (so the juice of the pineapple will not come out, as we have used pineapple juice for seasoning already).
Turn off the heat, add cashew nuts and mix. Serve hot.