Objective: how to cook chicken breast evenly

Which of the following solutions is more sound in terms of naive physics reasoning?

Available options: * place the chicken on cutting board then cover with Glad Press'n' Seal or saran wrap, and then whack it with a rolling pin or meat mallet until the chicken is the same thickness; * place the chicken on crock pot lid then cover with Glad Press'n' Seal or saran wrap, and then whack it with a rolling pin or meat mallet until the chicken is the same thickness;
place the chicken on cutting board then cover with Glad Press'n' Seal or saran wrap, and then whack it with a rolling pin or meat mallet until the chicken is the same thickness