Combine the peri peri sauce with the zest and juice of the lemon, add the crushed garlic cloves, the dried oregano and the olive oil and stir well; mix in the chicken chunks and coat with the marinade; cover and place in the fridge to marinate for at least 30 minutes
If using wooden skewers, soak them in water for at least 20 minutes; thread the red onions, red and green peppers and marinated chicken onto the skewers and cook on a hot barbecue for about 15 minutes
Serve in the fajitas with the mayonnaise, shredded lettuce and parsley or coriander sprigs
6 servings