Place chicken breasts in gallon zipper seal bag. Juice lemon and pour juice in bag. Seal and place in the refrigerator for about an hour, turning every now and then.
Place 1/4 cup of butter in a large skillet over medium high heat until melted. Add chicken breasts (and juice in bag) and cook, flipping as needed, until browned and no longer pink in the center, about 20 minutes.
In a small bowl, stir together remaining butter (1/4 cup), mayo, parmesan cheese, salt, and basil until fully blended.
Remove cooked chicken from skillet and place on baking sheet. Spread cheese mixture evenly over tops of chicken. Place in 350 oven for about ten minutes, or until cheese is melted.
Serve with slices of fresh lemon, if desired.
*If you'd rather use bottled juice just add about 3 tablespoons to the chicken in place of fresh. Please see post for more hints and tips.