I have to say that precooking chicken (to make it "soft") is something I really can't relate to (if you chose to use chicken breasts, anyway).
I think that precooking chicken, using chicken breasts (though BIRs probably don't use chicken breast), is unnecessary and saves very little time in the cooking process.
Frying it, and then cooking it with the curry, for 5 - 10 mins, or so, seems to result in a pretty acceptable "softness" to me ("flavour", however, might be a different question!).
The same is not true of other meats (e.g. lamb and beef) where a long, slow, cook is desirable to soften the meat (for the cheaper cuts anyway).