Chicken Pot Pie Casserole

Name: Chicken Pot Pie Casserole
Prep time: 15 min
Cook time: 1 h
Total time: 1 h 15 min
Cuisine: American
Ingredients: 1 (9-inch) pie crust (store bought or homemade); 4 tablespoons unsalted butter ((½ stick)); 2 tablespoons olive oil; 2 carrots (peeled and diced); 2 ribs celery (diced); 1 sweet yellow onion (peeled and minced); 2 cloves garlic (minced or pressed); 3 cups cubed cooked chicken; 4 ounces button mushrooms (cleaned and diced); 1 cup frozen peas (thawed); ¼ cup all-purpose flour; 2 cups low-sodium chicken broth (or stock); ¼ cup white wine (semi-dry or Chardonnay); 1 cup heavy cream (or half-and-half); ½ teaspoon kosher salt (or to taste); 1 teaspoon freshly ground black pepper; ½ teaspoon dried thyme; ¼ teaspoon ground sweet basil; 1 large egg (beaten slightly with 1 teaspoon water)