Roast Peppers: Turn your oven to broil. Place poblano peppers (about 2 medium) on a foil-lined baking sheet and lightly coat with olive oil. Broil until the skins are charred.
Prep Peppers: Carefully remove the hot peppers, place them in a glass bowl, and cover with plastic wrap for a few minutes. This makes peeling easy! Once cooled, peel the skins, remove the seeds, and chop. Reduce oven temperature to 350°F (175°C).
Cook Chorizo: In a large skillet, cook the ground chorizo sausage until beautifully browned. Drain off any excess fat and set aside.
Whisk Eggs: While the chorizo cooks, crack the eggs into a mixing bowl and whisk them vigorously for about 2 minutes until light and fluffy.
Sauté Onions: In the same skillet (or a clean one), quickly sauté the minced onions for a few minutes until softened.
Combine & Mix: Add the cooked chorizo, sautéed onions, chopped poblano peppers, diced tomatoes, heavy cream, garlic salt, and cayenne pepper (if using) to the whisked eggs. Stir everything together until well combined, but make sure to set aside 1 cup of the shredded cheddar cheese for later.
Assemble Casserole: Pour the mixture into a 9" x 13" baking dish that has been sprayed with non-stick spray. Sprinkle the remaining 1 cup of shredded cheddar cheese evenly over the top.
Bake: Bake for 30-35 minutes, or until the eggs are completely set and the top is golden brown.
Serve & Garnish: Let the casserole cool slightly before slicing. For an extra touch of freshness, garnish with more chopped fresh cilantro, slices of avocado, and crumbled queso fresco just before serving. Enjoy your delicious and healthy meal!