Creamy Chicken Casserole The Ultimate Comfort Food

Ingredients

• 1.5 lbs (680g) boneless, skinless chicken breasts, cut into 1-inch cubes
• 1 tbsp (15 ml) olive oil
• 1 medium onion, chopped (approx. 1 cup / 150g)
• 2 carrots, peeled and diced (approx. 1 cup / 120g)
• 2 celery stalks, diced (approx. 1 cup / 110g)
• 1 cup (120g) frozen peas
• 1 cup (120g) frozen corn
• 1/2 cup (50g) sliced mushrooms
• 1 tsp dried thyme
• 1/2 tsp dried rosemary
• Salt and pepper to taste
• 4 tbsp (57g) unsalted butter
• 4 tbsp (30g) all-purpose flour
• 3 cups (710 ml) chicken broth
• 1/2 cup (120ml) heavy cream
• 1/4 cup (60ml) dry sherry (optional)
• 1/4 tsp ground nutmeg
• 1 cup (100g) panko breadcrumbs
• 2 tbsp (28g) unsalted butter, melted
• 1/4 cup (25g) grated Parmesan cheese (optional)