Preheat the oven to 350°F (175°C) and prepare the baking dish.

Cook the crumbled sausage in a large skillet over medium heat for 5-7 minutes until browned.

Whisk the eggs and milk together in a mixing bowl until light and frothy.

Combine the cooked sausage, bread, and optional veggies into the egg mixture, then fold in the cheese.

Transfer the mixture into the prepared baking dish and spread evenly.

Bake for 30-35 minutes until golden brown and set in the middle.

Let the casserole cool for 5-10 minutes before serving.