Tear off two, 18-inch pieces of aluminum foil. Spray the center of each one with cooking spray and set aside.
Add the veggies to a mixing bowl, and drizzle with a tablespoon of the olive oil. Sprinkle with about half of the fresh herbs, and season with salt and pepper. Spoon about a cup of vegetables into the center of each foil packet.
Place a cod fillet on top of the veggies in each packet. Rub the rest of the olive oil on the cod fillets. Sprinkle with the rest of the herbs, and season with salt and pepper. Squeeze lemon juice over the cod and vegetables.
Fold each piece of foil in half over the fish and veggies. Roll in the sides to form a fully sealed foil packet.
Place the packets on the grill, close, and cook for 12 to 15 minutes until the fish is cooked through and veggies are tender. For reference, I cooked my packets for 13 minutes and they were perfect.
Serve with a fresh fruit salad or side of rice or quinoa for a balanced meal.
You can use other types of fish and veggies for these packets, but you may need more or less cooking time. In general, fish and veggie packets on the grill take 10 to 15 minutes to cook. I recommend only using veggies that are thin and soft like the veggies I used (tomatoes, green beans, zucchini). Asparagus, sliced bell peppers, eggplant, and corn kernels are all good options. Potatoes and root vegetables take longer to cook than fish, so they are generally not good options.
To make these packets in the oven instead of the grill, preheat the oven to 400 degrees F. Place the packets on a baking sheet and bake for 15 to 20 minutes.