Place the peppers skin side up under a hot grill until the skins are blackened (about 15 minutes), put them into a bowl, cover with clingfilm and leave to cool completely.
Brush the courgettes with a little oil and grill until browned, turning frequently, place on kitchen roll and leave to cool.
Peel the skins off the peppers and slice thickly.
Whisk the chilli oil and balsamic vinegar together and add salt and pepper to taste.
Wash and drain the lettuce leaves and tomatoes.
Lay the leaves in a bowl topped with the tomatoes, onion slices the grilled peppers and courgettes.
Drizzle with the balsamic dressing, top with fresh basil leaves and serve.