Add enough sunflower oil to a pan for deep fat frying and heat on a medium to high heat.
Meanwhile, take a small bowl and mix your yoghurt ingredients together.
Sprinkle corn flour onto a large serving plate and add your chayote wedges.
Move them around with yoır hands until they have a light coating.
Add one wedge to the oil to check if it's hot enough. If it bubbles and rises to the top, add the rest of your wedges.
Depending on the size of your pan, you may need to do this in batches.
After 4-5 minutes, when your chayote is browning a little, remove from the pan and drain on kitchen paper.
Serve your fried chayote squash with the yoghurt sauce.