There are two foolproof cooking methods for soft chicken breast. The first is low and slow: poach the chicken in a gentle simmer (not a boil) of broth or water for 15-20 minutes. It’s the same technique used for shredded chicken in enchiladas or chicken salad.
How To Cook Tough Chicken Breasts - Recipes.net
The second is high and fast: sear the pounded, brined chicken in a hot pan with a little oil for about 3-4 minutes per side. Then, let it rest for five minutes before cutting. Resting is non-negotiable—it lets the juices redistribute back into the meat instead of running out onto your cutting board.