Preheat oven to 350. Bake bottom pie crust for 10 minutes. Lower temp to 325.
In a saucepan heat olive oil and saute garlic and onion until translucent. Add chicken stock and frozen vegetables and bring to a boil. Remove from heat and mix milk and cornstarch and add to broth. Allow to cool slightly before adding the chicken, cheese and potatoes. Salt and pepper to taste. Pour into pie dish and cover with second pie crust. Cut slits into crust cook around 45 minutes or until crust is golden in color.