1. Heat oven to 375°F (190°C); grease a 9x13-inch dish.
Steam or blanch broccoli 3-4 minutes until just tender; drain.
Mix soup, sour cream, milk, cheddar, salt, and pepper in a large bowl.
Stir in chicken and broccoli to coat.
Spread evenly in prepared dish.
Top evenly with optional breadcrumbs.
Bake 25-30 minutes until bubbly and golden.
Cool a few minutes before serving.
Notes: You can use any cooked chicken, like rotisserie chicken, to make this recipe even quicker. Add a little extra kick by mixing in some red pepper flakes or a dash of hot sauce. This casserole freezes well! Just cover tightly and freeze for up to 3 months.
Thaw in the fridge overnight before baking.