In a medium saucepan combine the stock, chicken, peas, celery, and carrots. Bring to a boil.

Mix cornstarch with milk and stir into the stock mixture. Cook stirring constantly for 5 minutes. Remove from heat and let cool for 1 hour.

Preheat the oven to 325 degrees F (175 degrees C).

Stir cheese into the filling mixture and pour into a 9-inch pie crust. Top with second crust, seal edges, and cut slits in the top crust. Place on a cookie sheet and bake for 35 to 40 minutes or until the top crust is golden brown.