Mix the piri piri seasoning with 1 tablespoon of the oil and rub it over the swordfish steaks. Leave in the refrigerator to marinate for 30 minutes.
Place the tomatoes on a hot barbecue until they blacken slightly and become soft. This should take around 5–8 minutes. Remove, roughly chop and leave to cool slightly. Stir in the parsley, basil, chilli and lemon rind. Finally, add a little lemon juice and the remaining oil and season with salt and pepper.
Place the marinated swordfish on the barbecue and cook for 3–4 minutes on each side. Serve with the charred tomato salsa and lemon wedges.