BBQ:Char-grilled Tuna with fiery pepper puree

4 tuna steaks
finely grated rind and juice of 1 lime
2tbsp olive oil
salt & black pepper
FOR THE PEPPER PUREE
2 red peppers,seeded & halved
1 small onion
2 cloves garlic,crushed
2 red chillies
1 slice white bread without crusts,dried
3tbsp olive oil,plus some for brushing
lime wedges,to serve

Place the tuna in a dish.Sprinkle over the lime rind,juice,oil and salt and pepper.Cover and refrigerate until needed.To make the pepper puree,brush the pepper halves with a little oil and cook them,skin-side down,on a hot bbq,until the skin is blackened.Place the onion in its skin on the bbq and cook until browned,turning occasionally.Leave to cool slightly,covered with a clean cloth,and then remove the skins from the peppers and onions.Place the peppers,onion,garlic,chillies,bread and oil in a food processor.Process until smooth.Add salt to taste.Lift the tuna steaks from the marinade and cook them on a hot bbq for 8-10 mins,turning once,until golden brown.Serve with the pepper puree,lime wedges and crusty bread.