Layer the sausage, broccoli, spinach and cheese in a large casserole dish.
In a small bowl, whisk together the milk, eggs, salt and pepper
Pour the milk mixture over the top of the casserole. Press down on the casserole fillings to ensure they are all coated with the milk mixture
Bake the casserole in a 350 degree oven for 20-25 minutes or until the center of the casserole has set and is no longer liquid
Remove from the oven and serve while hot!