Whisk all the dressing ingredients in a medium bowl.
Add Sliced red Onion, Mix well and leave aside to marinate for an hour or more.
Place the ginger and salt in a mortar and pound well with a pestle – Add the garlic and continue pounding until its crushed and broken into pieces – Do not make a paste.
Add this to the bowl with Onion and dressing.
Cut Cucumbers lengthways in half and make slices 5 mm thick.
Add the cucumbers to the bowl and leave it to sit for 10 mins.
Before serving, stir the salad again, tip out some of the liquid accumulated below and adjust the seasoning – Sprinkle the toasted sesame seeds and serve.s