Place the breast on a cutting board and using a sharp chef's knife, cut a small slit into the chicken. Put your hand on top of the breast and insert the tip of the knife into the thickest part of the breast. Cut an opening (about 3 inches wide) and then cut 3/4 of the way through the breast to create a pocket. Try to avoid cutting all the way through the chicken. If you do, the filling will seep out. If you accidently do cut all the way through the breast, seal the other side with several toothpicks.