Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish with cooking spray or butter.
Place a large skillet on the stove over medium-high heat. Add the ground breakfast sausage and cook it until it is fully browned. Break the sausage apart with a spoon as it cooks. This will take about 6–8 minutes.
Once the sausage is cooked through, drain off any excess grease and set the sausage aside on a plate.
In the same skillet, add the frozen hashbrown potatoes. Cook them over medium heat for about 8–10 minutes, stirring occasionally, until they begin to thaw and lightly brown. They do not need to be fully cooked, just slightly softened.
Spread the hashbrowns evenly across the bottom of the prepared baking dish to create the first layer.
Spoon the cooked sausage evenly over the hashbrowns.
Sprinkle the shredded cheddar cheese evenly over the sausage layer.
Scatter the drained diced green chiles across the top of the cheese.
In a large mixing bowl, crack the eggs and add the milk, garlic powder, onion powder, and a pinch of salt and black pepper. Whisk everything together until the mixture is smooth and well combined.
Slowly pour the egg mixture evenly over the casserole so it soaks into all the layers.
Place the baking dish in the oven and bake uncovered for 35–40 minutes, or until the eggs are completely set and the top is lightly golden. A knife inserted in the center should come out clean.
Remove the casserole from the oven and allow it to rest for about 5–10 minutes before slicing and serving.
Enjoy!
