Begin by cooking the whole chicken in a pot of boiling water for about 35 minutes until fully cooked.

After the chicken is cooked, carefully remove it from the pot, discard the bones, and shred the meat. Place the shredded chicken into your casserole dish.

Chop the broccoli and carrots, and optionally add mushrooms for extra flavor and nutrients. Combine these vegetables with the shredded chicken in the casserole dish.

In a separate bowl, mix the can of chicken soup with sour cream and lemon juice until well combined.

Grate a slice of bread to make fresh breadcrumbs and grate the cheese.

Pour the prepared soup mixture over the chicken and vegetables in the casserole dish, ensuring even distribution. Sprinkle the breadcrumbs evenly over the sauce, then top with the grated cheese.

Bake the prepared baking dish in a preheated oven for 25 minutes or until the cheese on top is bubbly and golden brown, creating a deliciously crispy topping for your wholesome chicken casserole.

Once the chicken broccoli casserole is baked to perfection, remove it from the oven. Allow it to cool slightly before serving.

Scoop generous portions onto plates and enjoy this savory, cheesy Grandma's Chicken and Broccoli Bake with your favorite sides or a fresh salad for a complete meal experience.