Prep the chicken: Pat the chicken dry with paper towels and cut into even, bite-size cubes so they cook at the same rate.
Make the marinade: In a large bowl, whisk olive oil, lemon juice, zest, garlic, smoked paprika, cumin, oregano, onion powder, red pepper flakes (if using), salt, and black pepper.
Marinate: Add chicken to the bowl and toss to coat well.
Cover and refrigerate for at least 30 minutes and up to 8 hours. The longer it sits, the deeper the flavor.
Preheat the air fryer: Set to 380°F (193°C) for 4–5 minutes. Lightly brush or spray the basket with oil to prevent sticking.
Skewer the chicken: Thread the marinated chicken onto skewers, packing them snugly but not too tight.
If adding low-carb veggies, alternate pieces so everything cooks evenly.
Air fry, first side: Arrange skewers in a single layer without overlapping. Cook at 380°F (193°C) for 7 minutes.
Flip and finish: Turn the skewers and cook another 5–7 minutes, until the edges are browned and the chicken reaches an internal temp of 165°F (74°C).
Rest and garnish: Let skewers rest 3 minutes. Sprinkle with chopped parsley or cilantro and serve with lemon wedges.
Serve: Pair with cauliflower rice, a crunchy cucumber salad, or a creamy keto dip like avocado lime sauce or garlic yogurt (use full-fat, unsweetened).