Part 1: Preparation and Seasoning

1. Preheat Your Cooking Source:

   • For the Oven: Preheat your oven to 400°F (200°C).

   • For the Grill: Preheat your grill to medium-high heat, around 400°F (200°C).

2. Prepare the Foil: Tear off four large sheets of heavy-duty aluminum foil, each about 18 inches long. Using heavy-duty foil is important to prevent tearing and leaking.

3. Make the Seasoning Blend: In a small bowl, combine all the fiesta seasoning ingredients: chili powder, smoked paprika, cumin, garlic powder, onion powder, dried oregano, salt, black pepper, and optional cayenne pepper. Whisk them together until well combined.

4. Combine and Season the Ingredients: In a large mixing bowl, add the cubed chicken, chopped bell peppers, chopped red onion, rinsed black beans, and corn. Drizzle the olive oil and the juice from half a lime over the top.

5. Toss to Coat: Sprinkle the prepared fiesta seasoning blend all over the ingredients in the bowl. Use a large spoon or your hands to toss everything together until the chicken and vegetables are evenly and generously coated with the spices.

Part 2: Assembling the Foil Packets

1. Divide the Mixture: Spoon the chicken and vegetable mixture evenly onto the center of each of the four foil sheets. You should have a generous mound on each one.

2. Fold and Seal the Packets: This is the most crucial step to ensure proper cooking. For each packet:

   • Bring the two long sides of the foil sheet together above the food.

   • Fold the edges over two or three times to create a tight seal along the top.

   • Leave a little bit of space inside the packet for air to circulate (creating a “tent” shape).

   • Next, fold in the two short ends, crimping them tightly to completely seal the packet. Ensure there are no gaps where steam could escape.

Part 3: Cooking the Packets

You have two primary options for cooking, both yielding fantastic results.

Method 1: Oven-Baked

1. Place the sealed foil packets in a single layer on a large baking sheet. The baking sheet makes it easier to transfer them to and from the oven and will catch any potential leaks.

2. Bake in the preheated 400°F (200°C) oven for 20-25 minutes.

3. The cooking time can vary slightly depending on the exact size of your chicken and vegetable pieces.

Method 2: Grilled

1. Place the sealed foil packets directly on the preheated grill grates.

2. Close the grill lid and cook for 15-20 minutes, flipping the packets once halfway through the cooking time.

3. Grilling often cooks them a bit faster and adds a wonderful, subtle smoky flavor.

Part 4: Checking for Doneness and Serving

1. Check for Doneness: Carefully remove one packet from the oven or grill. Be extremely cautious when opening it, as hot steam will billow out. Open it away from your face. The chicken is cooked when it is no longer pink inside and a meat thermometer inserted into the thickest piece reads 165°F (74°C). The vegetables should be tender-crisp.

2. Serve Immediately: Once cooked, you can serve the packets directly to your guests or family. Let them carefully open their own packets. Garnish with your favorite toppings like fresh cilantro, cheese, a dollop of sour cream, and a squeeze from the remaining lime wedges.