If you find that your chicken breasts are sticking to the cast iron pan, a couple things may be happening. The most likely reason the chicken is sticking is it's not ready to be flipped yet. Give it another minute or two before trying to flip it. The other reason your chicken may be sticking to the cast iron is that the pan is not seasoned well enough. Check out this guide to learn how to season a cast iron skillet to help make the surface nonstick.