Preheat the oven to 400°F.

Bring water to a boil in a small saucepan over high heat. Add the quinoa and return to a boil. Reduce to a low simmer, cover pot, and cook quinoa until tender, 12-15 minutes.

Place quinoa, enchilada sauce, diced tomatoes with green chilies, corn, black beans, cilantro, cumin, paprika, Monterey jack, mozzarella, salt, and pepper in a large mixing bowl. Stir to combine with a rubber spatula. Transfer to a 9x9-inch baking dish and spread into an even layer.

Sprinkle the cheeses evenly over top of the casserole.

Bake the casserole on middle rack of oven until bubbling, 25-30 minutes.

Check to see that casserole is done. Remove from oven or add time as needed.

Serve casserole garnished with diced avocado, sour cream, and lime, if desired.