Preheat your oven to 350°F and grease a 13 x 9-inch casserole dish with butter or nonstick spray.

Using a serrated knife, cut the bagels into bite-size pieces (aim for 1-inch chunks). Set aside.

In a large bowl, whisk together the eggs, half-and-half, salt, and pepper until smooth. Toss the bagel pieces with the egg mixture until evenly coated, and let them sit to soak.

Heat the oil in a skillet over medium-high heat. Cook the sausage, breaking it into pistachio-sized chunks, until browned (about 5 minutes). Add the diced bell pepper and onion, cooking until softened (3-4 minutes). Drain any excess fat and let cool slightly.

Combine the sausage and veggie mix with the bagel mixture. Stir in 1 tablespoon of parsley and 2 cups of shredded cheddar until evenly distributed.

Pour the mixture into your prepared dish, cover with foil, and bake for 20 minutes. Remove the foil and bake for another 25 minutes, or until the top is golden and the center is set.

Immediately top with the remaining cheese and parsley. Let cool for 10 minutes before serving.