Succulent, moist chicken breast meat is the result you can get from poaching. This method of preparing chicken causes the breasts to shred easily. Just shred the chicken with forks, and add it to your enchilada recipe. The trick is to make sure you actually poach the chicken, not boil it. Boiling produces a drier chicken breast with less flavor.
Fill the saucepan halfway with water, and place it on a stove burner set to medium heat.
Add the onion to the saucepan for flavor, and bring the water to a simmer.
Add the chicken breasts to the saucepan, and wait until the water starts to simmer again.
Add the seasonings to the saucepan.
Cover the saucepan with its lid, and turn the temperature down to low.
Simmer the chicken breasts for about 20 minutes, or until the chicken is cooked through. Cut into the breasts with a knife to verify they are done; they should have no pink areas.
Remove the chicken breasts from the broth with a pair of tongs.
Pierce and hold the meat with one fork and pull the other fork through the meat to shred it.