Cooking 4kg of chicken to this recipe worked fine using the quantities listed so I'm fairly sure ifindforu meant to include "kg" in the ingredients. Certainly I can't see any BIR pre cooking 4 or 5 chicken breasts at a time.
The chicken is nice and tender in finished dishes and the flavour, although subtle, does come through. I simply piled the cooked meat into a big 2.6l lock n lock container and froze. Defrosting a portion of chicken involves chiselling 6 or 7 chunks (175g) from the frozen block by inserting a spoon handle between the gaps and twisting. But it's nothing like as awkward as it sounds and having a full 4kg of precooked chicken in a nice space efficient box in the freezer is very convenient.
My "ice cubes" of 1 tablespoon measure reduced cooking residue are also being pressed into use, adding flavour to the occasional curry when I feel it needs a boost. Don't go chucking that residue down the sink!!!