Leftover Turkey Pot Pie

Name: Leftover Turkey Pot Pie
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 3 tablespoons unsalted butter; 1/2 medium yellow onion, diced (about 3/4 cup); 2 small or 1 1/2 medium carrots, peeled and thinly sliced crosswise (about 3/4 cup); 2 small or 1 1/2 medium stalks celery, thinly sliced crosswise (about 3/4 cup); 1 1/2 teaspoons fresh thyme leaves, or 3/4 teaspoon dried thyme; 1/4 cup plus 2 tablespoons all-purpose flour; 1 1/2 cups low-sodium turkey or chicken broth or stock; 1 cup plus 2 tablespoons whole or 2% milk, plus more for brushing; 1 teaspoon kosher salt, plus more as needed; 1/4 teaspoon freshly ground black pepper, plus more as needed; 12 ounces shredded or diced boneless, skinless cooked turkey (about 3 cups); 1/2 cup frozen peas; 1 store-bought or homemade pie crust, thawed if frozen