01 - Set your air fryer to 350°F and allow it to preheat while you prepare the ingredients.
02 - In a mixing bowl, combine the sliced red bell pepper, zucchini, red onion, cherry tomatoes, Kalamata olives, garlic, chopped parsley, and dried oregano. Drizzle with half the olive oil and the lemon juice, then season with half the salt and pepper. Toss until the vegetables are evenly coated.
03 - Cut 4 sheets of parchment paper, approximately 12 × 16 inches each, and lay them flat on your work surface.
04 - Place one cod fillet in the center of each parchment sheet. Season the top side with the remaining salt and pepper.
05 - Divide the vegetable mixture evenly among the four fillets, mounding it on top. Arrange 2–3 lemon slices over each portion and drizzle with the remaining olive oil.
06 - Fold the parchment over each fillet and crimp the edges tightly to form sealed packets, enclosing the fish and vegetables completely en papillote style.
07 - Place the parchment packets in the air fryer basket, working in batches if needed to avoid overcrowding. Cook at 350°F for 13–15 minutes, until the cod is opaque throughout and flakes easily with a fork.
08 - Carefully open the parchment packets, watching for the hot steam. Serve the cod and vegetables either directly in the parchment or transferred to individual plates. Garnish with extra fresh herbs or capers if desired.