Step 1: Preheat Your Oven: Start by preheating your oven to 350°F (175°C). This ensures your casserole bakes evenly and comes out perfectly fluffy.
Step 2: Prepare the Baking Dish: Spray your 9x13 inch baking dish with olive oil spray to prevent sticking. Set it aside as you prepare the filling.
Step 3: Cook the Sausage: In a skillet over medium heat, add the sweet Italian chicken sausage. Use a spatula to break it apart and cook until browned and cooked through, about 5-7 minutes. Remove from heat and let it cool slightly.
Step 4: Sauté the Vegetables: In the same skillet, add 1 tablespoon of olive oil and heat. Add the chopped shallots and sauté until translucent, about 2-3 minutes. Then, add the sliced shiitake mushrooms and continue to cook for another 4-5 minutes until they are tender. Stir in the chopped roasted red bell peppers and broccoli, cooking until just tender, about 2 more minutes.
Step 5: Whisk the Eggs: In a large mixing bowl, whisk together the whole eggs, egg whites, and fat-free milk until well combined. Add the kosher salt and ground black pepper, mixing well.
Step 6: Combine Ingredients: Add the cooked sausage and sautéed vegetables to the egg mixture. Stir in the shredded mozzarella and grated Parmesan cheese until everything is evenly coated.
Step 7: Pour and Bake: Pour the entire mixture into the prepared baking dish, spreading it out evenly. Bake in the preheated oven for 30-35 minutes, or until the casserole is set and the top is lightly golden.
Step 8: Cool and Serve: Once baked, remove the casserole from the oven and let it cool for a few minutes. Cut into squares and serve warm. Enjoy your delicious Sausage, Cheese and Veggie Breakfast Casserole!
