Preheat the oven to 180 fan/gas 6. Peel and dice sweet potatoes, then place on an oven tray and bake for 25-30mins unsold tender. Leave to cool, then place in a bowl and mash until smooth with a fork.
Blend the kimchi and the mayonnaise together either in a bowl using a stick blender or in a food processor. Leave to one side.
Add the chilli, sweetcorn, coriander, salt, garlic and spring onions to the mashed sweet potato and mix well with your hands! Bring together into a ball and then divide into 8 equal pieces. Roll each piece into a ball with your hands and flatten to about 1cm thick.
Heat the oil in a frying pan and on a medium heat. Fry each cake for about 5 mins in total, turning halfway through. Set aside to keep warm.
Serve drizzled with kimchi mayo and sprinkle with more fresh coriander.