Start by preheating your oven to 350°F (175°C). A hot oven ensures even cooking and the perfect cheesy topping.
Take your steamed broccoli and spread it evenly across the bottom of your 9x13-inch baking dish. Whether you’re using frozen or fresh, make sure it’s not overly wet to prevent a soggy casserole.
Lay chopped, cooked chicken evenly atop the broccoli. This layering ensures every forkful has a mix of protein and veggies.
Combine the cream of chicken soup, cream of mushroom soup, mayonnaise, and lemon juice in a bowl. Stir with a whisk until everything is blended into a smooth, creamy sauce.
Pour the sauce gently over the chicken and broccoli, spreading it evenly to cover the casserole. The sauce locks in moisture and brings loads of flavor.
Top the entire casserole with shredded cheddar. This golden, bubbly layer is one of the highlights of the dish.
Bake in the preheated oven for 35–40 minutes or until the dish is bubbling and the cheese is lightly browned. If you prefer a crisp topping, consider broiling it for 1–2 more minutes.
Once done, remove the dish from the oven and allow it to cool slightly for 5–10 minutes. This makes it easier to serve.