Lightly grease a 9x13 inch baking dish. Line the bottom of the dish with 4 tortillas. Sprinkle with 1/3 each of the green onions, olives, chile peppers, pimento peppers, Monterey Jack cheese, and Cheddar cheese. Repeat twice with the remaining ingredients.
In a large bowl, beat together eggs, milk, and salsa. Pour over the layered ingredients. Cover with plastic wrap, and refrigerate overnight.
Remove the casserole from refrigerator, and remove plastic wrap. Preheat oven to 350 degrees F (175 degrees C).
