How to not dry out precooked meat in a recipe
You're not expecting the same texture if you re-cook, that's why many re-cook recipes involve shredding the meat before the second part of the process - separating it as long fibres.
Chicken Tinga, Pulled Pork, etc use this as the basis of the texture of the dish.
Using fattier cuts can mitigate the drying out.

Personally, if I have a long cook that's going to be using chicken breast, I often don't put the chicken in until near the end, so I can get it 'first time' rather than second. It will affect absorption of other flavours though. Something like a curry you can tweak this approach by marinating the chicken in a similar spice blend. Sometimes I just make the call based on experience with a particular dish, or try it both ways &amp; see which I prefer.

If you par-cook the meat, you will then have an extended period where the centre is in a completely unsafe temperature zone.
Don't do this.

From comments
For a pie - so long as it's going straight in the oven, you can flash-fry chicken chunks to get some good colour then finish in the oven, in the pie-mix. So long as the mix doesn't start from cold, temperatures ought to remain in the safe zone throughout.