Rinse quinoa thoroughly in a fine sieve and drain. Bring water or stock and a generous pinch of salt to a boil in a saucepan; add quinoa and return to a boil. Stir, cover and reduce the heat. Simmer until quinoa is tender but still chewy, about 15 minutes. Fluff with a fork and let cool slightly.

In a large bowl, combine quinoa, enchilada sauce, green chiles, beans, corn, chili powder, cumin, coriander and cilantro; season with salt and pepper. Stir in half of the cheese.

Spread mixture in a 2-quart baking dish; top with remaining cheese.

To bake right away: Preheat oven to 375° F. Wrap casserole in foil and bake, covered, for about 30 minutes. Remove foil and bake until cheese is bubbly and beginning to lightly brown, another 5 to 10 minutes. Serve with diced avocados, tomatoes and sour cream.

If freezing: Allow mixture to cool, wrap dish in foil, label and freeze. To bake after freezing, preheat oven to 375° F. Bake casserole, covered and unthawed, for about 50 minutes. Remove foil and bake until cheese is bubbly, about 10 additional minutes. Serve with diced avocados, tomatoes and sour cream.