Comforting Chicken Burrito Casserole

Name: Comforting Chicken Burrito Casserole
Ingredients: 1 pound boneless, chicken breast (cooked and shredded); 1 yellow or red onion, diced; 1 cup white rice (uncooked); 1 teaspoon cumin; 2 teaspoons chilli powder; 1 tablespoon oregano; 1 teaspoon garlic powder; 1 teaspoon sea salt; 1 teaspoon ground black pepper; 2 1/2 cups chicken broth; 3 tablespoons tomato paste; 1 tablespoon olive oil; 1 can (14 oz) black beans, drained; 1 can (14 oz) corn, drained; 1/2 cup mexican blend cheese (or non-dairy cheese shreds); chopped cilantro; chopped green onion; diced avocado