Chicken Pot Pie Casserole Recipe Easiest Comfort Food

Ingredients

• 2 tablespoons (30 ml) olive oil
• 1 large onion, chopped (about 1 cup / 150g)
• 2 carrots, peeled and chopped (about 1 cup / 120g)
• 2 celery stalks, chopped (about 1 cup / 100g)
• ½ teaspoon dried thyme
• ¼ teaspoon dried rosemary
• 4 tablespoons (60g) unsalted butter
• ⅓ cup (40g) all-purpose flour
• 3 cups (720 ml) chicken broth
• 1 cup (240 ml) whole milk
• 1 teaspoon salt, or to taste
• ½ teaspoon black pepper, or to taste
• 2 cups (300g) cooked chicken, shredded or diced (about 2 large chicken breasts)
• 1 cup (150g) frozen peas
• 1 cup (150g) frozen corn
• 1 ½ cups (190g) all-purpose flour
• ¾ teaspoon baking powder
• ½ teaspoon salt
• ½ cup (113g) (1 stick) cold unsalted butter, cubed
• ½ cup (120 ml) cold milk
• 1 large egg
• 1 tablespoon milk