Preheat oven to 375 F. Lightly oil the pan (I had 10 x 8 pan) or coat with nonstick spray.
In a large bowl combine corn, rice, black beans, chive, cilantro, chili powder and taco sauce. Mix all ingredients together.
Spread rice mixture in the pan, lay shredded mozzarella cheese on top.
Bake for 20 minutes until the cheese will melt.
In the meantime dice the tomato, avocado and red onion. In the small bowl mix all ingredients. Add some chopped chive and cilantro. Season with salt and pepper to taste.
After baking put fresh ingredients on top of the casserole.