Prep the fish: Pat the harders dry with paper towels. Dry skin is key to crisping. Make 2 shallow diagonal slashes on each side of each fish to help the seasoning penetrate.
Season: Rub fish with olive oil, salt, pepper, and paprika.
If you like, tuck a thin lemon slice into the cavity of each fish for a hint of citrus.
Preheat the air fryer: Heat to 400°F (200°C) for 3–5 minutes. A hot basket prevents sticking and kickstarts crisping.
Mix the chermoula: In a bowl, combine cilantro, parsley, garlic, cumin, paprika, chili (if using), lemon zest, lemon juice, olive oil, and salt. Stir to form a loose, spoonable sauce.
Taste and adjust salt and lemon.
Arrange the fish: Lightly oil the air fryer basket or use a perforated parchment liner. Place fish in a single layer without overlapping. Work in batches if needed.
Air fry: Cook for 8–12 minutes, flipping once halfway.
Time depends on fish size and your air fryer model. The skin should be browned and crisp, and the flesh opaque and flaky.
Finish: Transfer the fish to a platter. Spoon chermoula over the top, leaving extra on the side for dipping.
Serve: Add lemon wedges for squeezing.
Pair with bread to catch the juices and a simple salad for crunch.