1 cucumber, cut in half lengthways, seeds scraped out, flesh finely diced
3 tbsp chopped fresh dill
3 tbsp chopped fresh coriander leaves
2 garlic cloves, crushed
2 limes, juice only
3 tbsp chopped fresh mint leaves
1 banana shallot, finely diced
16 sardines, scales and guts removed (ask your fishmonger to do this for you)
sea salt and freshly ground black pepper
4 tbsp extra virgin olive oil