Preheat oven to 350 degrees F. Spray 9x13" baking dish with cooking spray.
In a large skillet, cook Italian sausage or chorizo over medium-high heat.
Once done, remove from skillet. If there is a lot of grease, wipe a little excess off but leave some for sauteing the onions and bell peppers.
Add onions and bell peppers to skillet and cook 5-7 minutes, until they begin to soften.
Remove from heat.
In large bowl, whisk together eggs, milk, and enchilada sauce.
Place tortillas on microwave-safe plate and cover with damp paper towel.
Microwave for 30-60 seconds, until the tortillas are soft and able to roll.
Fill each tortilla with equal amounts of onion/bell pepper mix and the cooked sausage. This was about 2-3 tbsp total.
Place seam down into prepared baking dish. Repeat with remaining tortillas.
Pour egg mixture over enchiladas.
Top with cheese and cover with aluminum foil.
Bake in preheated oven for 30-35 minutes, until eggs are set.
Remove aluminum foil and bake an addition 10-15 minutes.
Serve topped with green onions, sour cream, salsa, cilantro, hot sauce, etc.