Forget a plain ol' egg and cheese bagel. Turn it into a make-ahead breakfast casserole instead!
Preheat oven to 350° and grease a 9”-x-13” baking pan with cooking spray. Scatter about half of the bagel pieces in the baking pan then top with half of the cheddar, tomatoes, cream cheese, and red onion. Repeat to make another layer.
In a large bowl, whisk together eggs, milk, and green onions. Season with salt, pepper, and a pinch of cayenne pepper. Pour mixture over bagels making sure to coat each bagel piece. Sprinkle seasonings over casserole then cover with foil and bake for 45 minutes. Remove foil and bake until bagels are golden and eggs are cooked through, about 25 minutes more. Let cool 30 minutes.
Garnish with green onions before serving.