Mexican Chicken Casserole

Ingredients

• 2 tablespoons extra-virgin olive oil
• 1 onion, chopped
• 1 bell pepper, color of your choice, chopped
• 2 cloves garlic, minced
• 1 (15.5-ounce) can black beans, rinsed and drained
• 1 (15.25-ounce) can corn, drained
• 3 cups chicken, cooked and shredded
• 1 (4.5-ounce) can diced green chiles
• 2 (10-ounce) cans enchilada sauce, divided
• 18 (6-inch) corn tortillas
• 2 cups cheddar cheese, shredded
• 2 cups Monterey Jack, shredded
• sour cream, to taste
• fresh cilantro, to taste, roughly torn
• avocado, to taste, diced