Step 1: Prep and Sauté the Aromatics

1. Preheat the oven to 375°F (190°C).
2. In a large skillet, heat olive oil over medium heat.
3. Add the chopped onion and cook until softened, about 4-5 minutes.
4. Stir in the minced garlic and cook for an additional minute until fragrant.

Step 2: Cook the Ground Beef

1. Add the ground beef to the skillet and cook, breaking it up with a spoon, until fully browned.
2. Season with a pinch of salt and pepper, then drain any excess fat from the skillet.

Step 3: Add Seasonings and Rice

1. Stir in the minced chipotle peppers, cumin, smoked paprika, and chili powder (if using).
2. Add the uncooked rice, stirring to coat it well with the spices and beef mixture.

Step 4: Incorporate Tomatoes and Corn

1. Pour in the diced tomatoes (with their juice) and corn kernels.
2. Mix everything together until well combined.

Step 5: Add Broth and Bake

1. Gradually pour in the beef or chicken broth, stirring to combine.
2. Transfer the mixture to a greased 9×13-inch casserole dish, spreading it out evenly.
3. Cover the dish with aluminum foil and bake in the preheated oven for 35-40 minutes, or until the rice is tender and has absorbed most of the liquid.

Step 6: Add Cheese and Finish Baking

1. Remove the foil and sprinkle the shredded cheese evenly over the casserole.
2. Return the dish to the oven and bake uncovered for an additional 5-10 minutes, or until the cheese is melted and bubbly.

Step 7: Garnish and Serve

1. Remove the casserole from the oven and let it sit for a few minutes.
2. Garnish with freshly chopped cilantro and serve with a dollop of sour cream if desired.