1. Preheat Oven to 450
2. Place Cod on a piece of aluminum foil, season with Salt and Pepper, Garlic Powder. Top cod with with spinach, tomatoes, and onion; Season again with salt and pepper. Drizzle olive oil & balsamic vinegar over cod and top with mozzarella Cheese.
3. Fold the foil over Cod creating a packet, crimping the edges to make a seal
4. Cook for 10-20 min.; Rest and Serve!