1-First Step: Preheat and Prepare Your PanBegin by preheating your oven to 350 degrees Fahrenheit. While the oven heats up, prepare your baking dish. Grease a 9×13 inch pan thoroughly with cooking spray, making sure to coat the bottom and sides completely. This ensures that your casserole won’t stick and will release easily after baking. For an extra layer of insurance, you can also line the pan with parchment paper with overhanging edges, which creates handles for easy removal later. Taking time to properly prepare your pan will make serving much easier and ensure your beautiful casserole comes out in one piece.

2-Second Step: Prepare the Egg MixtureIn a large mixing bowl, crack all 12 eggs. Add the sour cream, milk, salt, and pepper. Using an electric mixer on low speed, combine these ingredients until they’re well mixed and slightly frothy. This should only take about 1-2 minutes be careful not to overmix as this can make the texture too dense. Once combined, stir in the shredded cheddar cheese until it’s evenly distributed throughout the egg mixture. The cheese will melt and create beautiful pockets of gooey goodness as the casserole bakes. For those who prefer a lighter texture, separate your eggs and beat the whites separately before folding them in at the end this creates an even fluffier result.

3-Third Step: Cook the SausageIn a large skillet over medium heat, cook the sausage. Use a spatula or wooden spoon to break the meat into small, bite-sized pieces as it cooks. Continue cooking until the sausage is browned and cooked through, about 7-10 minutes. Once done, carefully drain most of the grease from the skillet, leaving just a small amount behind for flavor. Adding the sausage to your egg mixture while it’s still warm will help melt some of the cheese and create an even more cohesive mixture. Be sure to drain well though excess grease can make the casserole heavy and oily rather than fluffy and light.

4-Fourth Step: Prepare the VegetablesIn the same skillet you used for the sausage (no need to wash it first), add the diced green and red bell peppers along with the sliced green onions. Sauté these vegetables over medium heat for 2-3 minutes until they’re slightly softened but still have a bit of crunch. This quick cooking process brings out their natural sweetness and mellows the sharp onion flavor. Once done, add the vegetables to your egg and sausage mixture, stirring everything together until well combined. The colors of the peppers will make the casserole visually appealing with specks of red and green throughout.

5-Final Step: Bake and ServePour the entire mixture into your prepared 9×13 inch pan, spreading it evenly with a spatula. If desired, top with an extra sprinkle of cheese for a beautiful golden crust. Place the pan in the preheated oven and bake for 35-50 minutes. You’ll know the casserole is done when the edges are set and slightly golden, while the center is still slightly jiggly. This residual jiggle is important it means the eggs are perfectly cooked and will continue to set as the dish cools. Remove from the oven and let the casserole rest for about 10 minutes before serving. This resting period allows the flavors to meld together and makes for cleaner cuts when serving.