In a skillet over medium heat, cook the sausage, onion, and green bell pepper until the sausage is browned and the vegetables are tender. Drain excess grease.
In a large bowl, whisk the eggs and milk together. Add salt and pepper. Stir in the cooked sausage mixture, thawed hash browns, and half of the cheese.
Grease a 9x13-inch baking dish and pour the mixture into the dish. Sprinkle the remaining cheese on top.
Cover with foil and bake in the preheated oven for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the top is golden brown and the eggs are set.