Step 1: Preheat your oven to 350°F (175°C) to ensure even cooking.
Step 2: In a large pot, bring water to a boil. Add the broccoli florets and cook until tender-crisp, about 3-4 minutes. Drain and set aside.
Step 3: Season chicken breasts with salt and pepper, then cook in a skillet over medium heat until no longer pink, about 6-7 minutes per side. Shred into bite-sized pieces.
Step 4: In a large mixing bowl, combine cream of chicken soup, milk, mayonnaise, salad dressing, lemon juice, and half of the cheddar cheese. Mix until smooth.
Step 5: Add cooked chicken and broccoli to the bowl with the sauce. Stir gently until well coated.
Step 6: Pour the mixture into a greased 9x13 baking dish and spread evenly.
Step 7: Sprinkle remaining cheddar cheese, followed by bread crumbs and Parmesan cheese. Dot with butter pieces.
Step 8: Bake for 25-30 minutes until the top is golden brown and cheese is bubbly.
Step 9: Let cool for a few minutes before serving. Enjoy!