Preheat oven to 450°.
In large pot melt butter and saute onions and celery over medium heat for 3-4 minutes until soft.
6 tablespoon butter, 1 large onion, 2 celery ribs
Add salt, pepper, and thyme for 30 seconds. Add in flour and whisk, cooking for 1-2 minutes.
½ teaspoon kosher salt, ¼ teaspoon ground pepper, ½ teaspoon dried thyme, ½ cup flour
Slowly add in the milk and chicken broth a little at a time. Bring to a gentle simmer and cook for 3-5 minutes until thickened.
1½ cups milk, 1½ cups chicken broth
Add sherry and cook for 1 minutes. Finally, dump in the chicken and frozen vegetables. Stir until well combined.
3 tablespoon dry sherry, 3 cups rotisserie chicken, 1 10 ounce frozen peas and carrots, 3 tablespoon fresh parsley
Pour into a 9x13 pan. Top with crust. If desired, put on egg wash. See note section below. Bake for 30 minutes. Allow to rest for 10 minutes before serving.
store-bought pie crusts