Preheat the oven to 400°F/200°C.
In a ceramic-coated cast-iron pan or other oven-proof skillet, cook the chorizo according to the instructions or until cooked through. Remove from the skillet and set aside.
Add 1 tablespoon olive oil to the skillet over high heat. Add in the onions and a pinch of salt. Cook for 2-3 minutes or until they begin to turn translucent.
Add in the peppers, Fresno chili (or jalapeño), and garlic along with another pinch of salt. Stir frequently to avoid burning the garlic. Cook for 2-3 more minutes or until the peppers have begun to soften.
Add in the can of mild diced green chilis. Stir to incorporate.
Add in the can of fire-roasted tomatoes and the remaining salt and pepper. Make sure to include all the juice from the can of tomatoes. Mix well.
Add the cooked chorizo back into the pan. Mix well.
Create 4-6 small wells (depending on the number of eggs you are using) in the chorizo and veggies.
Sprinkle the cotija on top of the chorizo and veggie mix. If you are paleo, omit this step.
Add the eggs to the wells.
Sprinkle the cilantro over the top of the dish.
Place the skillet into the oven for 5-7 minutes, or until the eggs are set to the desired temperature.
Serve directly from the skillet. If you have extra cotija around, sprinkle on top and serve hot.