Brown the chorizo over medium heat in a skillet. A few minutes before the chorizo is fully cooked, add in the bell peppers, onion and green chiles. Cook until the chorizo has reached an internal temperature is 160°F.
In a mixing bowl, combine eggs, milk, sour cream and seasoning and whisk very well for about 2 minutes until smooth and all the sour cream is smooth. You can use an electric hand mixer for this part for quick and easy mixing.
Get rid of as much grease as you can from the chorizo after browning. Chorizo can release a decent amount of grease and when it's mixed into the egg bake, it will all swell over top and make the casserole very greasy. For best results, drain the chorizo mixture well, pat it with a paper towel or even spread it over a paper towel lined baking sheet briefly to allow it to absorb.
You can make this chorizo breakfast casserole 24 hours ahead of the time. Prepare all of the ingredients and store in an air tight container for one day before baking. Stir up the mixture, transfer to the greased pan and allow the casserole mixture to sit at room temperature for about 15-20 minutes before baking.
Serve this in tortillas as tacos! A great way to enjoy eggs for dinner is to turn this egg casserole into tacos. Break up the casserole after baking and spoon into warm tortillas and then top with favorite toppings.
To ensure food safety, eggs should be cooked until both the yolk and the white are firm. Consuming raw or undercooked eggs may increase your risk of foodborne illness, especially for those with certain medical conditions. For recipes that call for eggs that are raw or undercooked when the dish is served, use either pasteurized shell eggs that have been treated to destroy Salmonella, or use pasteurized egg products.