Pick the meat off the Rotisserie Chicken while it is still warm - it is easiest then. Cut the removed chicken into bite-size pieces and place into a large mixing bowl. Discard the skin and bones.
Place one of the pre-made Pillsbury Pie Crusts into the bottom of a 9-inch deep-dish pie plate that has been sprayed with Pam.
Make a Bechamel Sauce in a stock pot (instructions below).
Once you finish making the Bechamel Sauce, turn off the heat. Add the chicken and drained mushrooms to the stock pot and mix well.
Next, add the drained peas and carrots to the sauce in the stock pot. Mix gently, making sure they do not get smashed.
Pour the entire sauce mixture with the chicken and vegetables on top of the bottom crust in the pie plate.
Top with the other pie crust and crimp the edges together, sealing the pie. Make a few knife cuts on top for venting,
Bake in a preheated 350° oven for 1 hour. Halfway through the baking process, place a ½ inch, narrow circle of foil on the outer pie crust to prevent the edges from burning.
Allow the Pot Pie to rest for 10-15 minutes before slicing.