Absolutely you can! It's a great idea to make extra chicken for just this purpose. To freeze the chicken, spread it out in a single layer on a parchment paper lined baking sheet and stick it in the freezer for a couple of hours or overnight. Then, move the chicken to air tight containers. This prevents the chicken from sticking together, allowing you to take out just as much as you want later. The chicken should maintain its quality for 2-3 months in the freezer.