Question: When I cook chicken, it always comes out tough. Am I cooking it too long, too short, too high or too low?
The slower you cook chicken, the better. That's the overall rule for cooking protein. Start by having the heat medium-high when you put the chicken breast in the pan. Sear it quickly. Then get the heat down to medium-low. The average-size boneless chicken breast takes only about 6 minutes of cooking time. When it's fully cooked, it should be firm when you press it.
When you roast chicken there are some variables. One technique uses very high heat to make a very succulent roasted chicken: Roast a chicken with the skin on at 475 degrees Fahrenheit for 10 minutes to the pound plus 15 minutes. Your oven will get splattered, but you will have tender chicken as long as you keep the skin on. (Another technique: a vertical roaster.)
These days, lots of people like to take the skin off the chicken to cut down on fat. If you do this, you need to cook it slowly at 350 degrees Fahrenheit.