Begin by preheating the oven to 375.
Take the sausage and cook it in the pan on the stove. cook the meat and break it into smaller pieces until the meat is browned and fully cooked.
Chop the bell peppers, serrano chili, green onions, and zucchini into smaller pieces. I like to dice them into small squares but I make sure to cut the zucchini smaller then the rest so that they are less prominent.
Crack the eggs into a medium sized bowl.
Add the chopped veggies to the eggs.
Using a spoon with holes or a strainer, transfer the sausage to the bowl with the rest of the ingredients. Make sure to drain as much of the grease as you can.
Add the salt and pepper to the bowl and stir everything together.
Pour the whole bowl into the casserole pan and sprinkle as much cheese as you would like on top.
Place the pan into the oven and cook for 25 minutes or until the egg is fully cooked through and not "jiggling" when you move the pan.
Remove from the oven, cut and serve.