Chicken Casserole with Rice

Combine flour, salt, and pepper in a large saucepan; slowly whisk in milk. Cook over medium heat until thick and bubbly, 5 to 10 minutes. Continue cooking for 2 more minutes. Remove from heat and add Muenster and Cheddar cheeses. Let sit for a few minutes and then stir until cheeses have melted.

Preheat the oven to 350 degrees F (175 degrees C).

Stir cooked rice and cooked chicken into the cheese sauce and pour into a 9x13-inch casserole dish.

Mix bread crumbs and melted butter together in a small bowl. Spoon over the top of the casserole.

Bake in the preheated oven until bubbling and heated through, about 30 minutes.