Mexican Cornbread Casserole

For the filling:

• 1 medium onion (finely chopped)
• 1 bell pepper (finely chopped)
• 2 tablespoons olive oil
• 1 pound ground beef
• 3 tablespoons taco seasoning (equivalent of 1 packet)
• 1 (15 ounce) can corn drained, southwest style
• 1 (8 ounce) can tomato sauce
• 1 (4 ounce) can diced green chiles
• 1 (10 ounce) can tomato like Rotel, diced
• 1 (10 ounce) can green chile like Rotel, diced
• salt to taste
• black pepper to taste
• 1 cup cheese cheddar or Mexican blend, shredded

For the cornbread:

• 1 (8 ounce box) Jiffy corn muffin mix
• 1 large egg
• 1 cup sour cream
• 1 (15 ounce) can creamed corn
• 2 cups cheese cheddar or Mexican blend) Divided, shredded

Optional toppings:

• sour cream
• avocado diced
• cilantro
• cheese shredded
• diced tomatoes
• green onion