Preheat oven to 375 degrees F and coat a baking dish or 8×8 deep dish with non stick spray or butter.
Add enchilada sauce, egg, seasoning, spices, and mayonnaise to a large bowl. Whisk well until smooth. Add in pre-cooked chicken and cauliflower. Toss to coat. Stir in Monterrey jack cheese. Top with additional cheese, olives, green onion, and extra sauce if desired.
Bake for 55-60 minutes until top is bubbly, golden brown, and cauliflower is tender.