Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking dish.

In a large bowl, whisk together the eggs, sour cream, milk, cheddar cheese, salt, and black pepper until just combined.

Heat a large skillet over medium heat. Add the beef sausage and cook until browned, breaking it into small pieces. Drain excess fat.

Add the cooked sausage to the egg mixture.

In the same skillet, sauté the bell peppers and green onions for 2–3 minutes until slightly softened. Add to the bowl.

Stir everything together, then pour the mixture into the prepared baking dish.

Bake for 35–50 minutes, until the edges are set and the center is slightly jiggly.

Let rest for 5–10 minutes before slicing and serving.