1. Combine the oil, red wine vinegar, and rosemary in a non-reactive bowl. Season with salt and pepper to taste. Mix well. Add the chicken fillets, turn to coat all sides and let stand for at least 1 hour. Transfer chicken and marinade into a baking dish that can fit into your Air Fryer basket. Preheat your Air Fryer to 400 F (200 C).
2. Cook the chicken for 20 minutes or until golden brown and cooked through, turning once halfway through cooking time.