This is very similar to all the other Mexican Casseroles out there, whether they're from Mary McDougall or the Engine 2/Forks over Knives folk. This one is from the September 2004 McDougall newsletter:
Easy Taco Casserole
As I have mentioned many times before, my family really likes spicy, Mexican flavored foods. We like to come up with variations, such as the previous recipes for Mexican Pasta Surprise and Polenta with Black Beans, and this is another one that is so simple anyone can prepare it in almost no time at all. We like to roll this up in a tortilla, but it can also be served over rice or a baked potato.
Preparation Time: 10 minutes
Cooking Time: 45 minutes
1 onion, chopped
1 bell pepper, chopped
1 15 ounce can black beans, drained and rinsed
1 15 ounce can pinto beans, drained and rinsed
2 cups frozen corn kernels
1 ½ cups salsa, mild, medium or hot
1 package Bearitos Taco Seasoning
Preheat oven to 350 degrees.
Combine all ingredients in a casserole dish. Cover and bake for 30 minutes, uncover and bake for an additional 15 minutes.
Hints: Some grated soy cheese may be sprinkled over the top of the casserole for the final 15 minutes of baking, if desired.