In a saucepan boil the sweet potato until half done (they should be soft but not completely done). Remove from saucepan, let cool for 10 minutes and coarsely grate the potatoes.

In a bowl, beat together the eggs and the buttermilk; add the flour and mix until well blended.

Add corn and coriander, flavor with salt and pepper then add in the grated sweet potato. Mix well.

To make the fritters, heat olive oil in a non-stick pan over moderate flame. Once oil is hot, use 2 tablespoon of potatoes mixture for every fritter to be made, place the mixture (2 tablespoon) into the pan and spread to make a circle. Fry until light brown and firm (about 2 minutes on each side). Repeat for the entire mixture.

Remove from heat; serve each fritter topped with a tablespoon of yoghurt.