01 - Preheat your air fryer to 350°F (180°C).
02 - In a mixing bowl, combine the bell pepper, zucchini, red onion, cherry tomatoes, olives, garlic, parsley, and dried oregano. Drizzle with half the olive oil and the lemon juice, then season with salt and pepper. Toss until evenly coated.
03 - Cut 4 large sheets of parchment paper, approximately 12 × 16 inches each.
04 - Place one cod fillet in the center of each parchment sheet. Season generously with salt and pepper.
05 - Spoon the seasoned vegetable mixture evenly over each fillet. Arrange 2–3 lemon slices on top of each portion, then drizzle with the remaining olive oil.
06 - Fold the parchment paper over each fillet and crimp the edges firmly to create tightly sealed packets (en papillote style).
07 - Place the sealed packets in the air fryer basket, working in batches if needed. Cook for 13–15 minutes until the cod is opaque and flakes easily with a fork.
08 - Carefully open the parchment packets and serve immediately, either directly in the parchment for presentation or transferred to plates.