Preheat the grill to its highest setting. Line a baking tray with aluminium foil.
For the roasted red pepper salad, when the grill is hot, place the peppers onto the prepared baking tray and grill for 10-12 minutes, turning occasionally, until the skin is blackened and blistered on all sides.
Transfer the blackened peppers to a bowl, cover with cling film and set aside for 10-15 minutes, or until the skins have loosened and the peppers are cool enough to handle.
Peel and discard the blackened skin from the peppers using your fingers. Cut each peeled pepper in half over a serving bowl, catching any juices in the serving bowl.
Remove the seeds from the peppers, then tear the flesh into long strips 1cm/½cm wide, using your fingers. Add the pepper strips to the serving bowl.
Add the anchovies, garlic and capers to the bowl containing the peppers. Twist the lemon rind strips and add them to the bowl, then pour over the lemon juice and olive oil. Season, to taste, with salt and freshly ground black pepper. Mix the salad ingredients until well combined and coated in the dressing. Set aside for at least one hour to allow the flavours to infuse.
Meanwhile, light the barbecue. When the flames have died down and the coals have turned ash-white, the barbecue will be ready (this should take about 30 minutes).
For the sea bass, run the sea bass under cold water, then pat dry with kitchen paper. Rub the sea bass all over with the olive oil, then season, to taste, with salt.
Place the sea bass onto the barbecue grill and cook for 12-15 minutes on each side, or until the skin is crisp and golden-brown on both sides and cooked through. (NB: The sea bass is cooked through when the tip of a knife inserted into the thick meat behind the head meets with only the faintest resistance near the bone.)
To serve, add the chopped mint and basil to the salad, if using, and mix well to combine. Place one barbecued sea bass onto each of four or five plates, and spoon the roasted red pepper salad alongside.