1. In case of whole chicken breasts, it will take about 10 to 15 minutes to cook completely under cold water. Make sure the water is boiling before adding the chicken and keep the water boiling during cooking.

2. If the chicken breast is in pieces, it will take about 8 minutes to cook if cooked under cold water.

3. If cooking in the oven, chicken breasts will take about 25 to 30 minutes to cook in a preheated 375 degree F (about 190 degree C) oven. Oven cooking times will vary depending on the size of the chicken and the oven temperature.

Chicken breasts contain a lot of protein, vitamins, phospholipids, and nutrients such as calcium, iron, and phosphorus, and are generally cooked through, and should not be cooked for too long to avoid aging the meat.