Brown the Meat: While the peppers are baking, brown the ground beef (or chorizo) in a large skillet over medium heat. Midway through the browning process, add the diced onion and continue cooking until the meat is browned and the onion is soft. Drain any excess grease from the skillet.
Add Aromatics and Spices: Turn the heat to low and add the minced garlic, chili powder, and ground cumin. Cook for 1 minute, stirring constantly.
Combine Ingredients: Stir in the cooked rice, corn, black beans, and fire-roasted tomatoes. Allow the mixture to simmer for a few minutes over low heat. If the mixture becomes too thick, add a couple of tablespoons of beef broth, chicken broth, or water. Season with kosher salt and freshly ground black pepper.
Incorporate Cheese and Cilantro: Remove the mixture from the heat and let it cool for a few minutes. Stir in 1 cup of shredded cheese and 2-3 tablespoons of chopped cilantro.
Stuff the Peppers and Bake
Fill the Peppers: Spoon the filling mixture into the prepared poblano peppers and top with the remaining cheese.
Bake: Return the stuffed peppers to the oven and bake for 10-15 minutes, or until the cheese is melted and the peppers are heated through. Sprinkle with the remaining chopped cilantro before serving.
