Peel the skin off the sweet potato and slice it lengthways into 3cm thick slices. Cut the corn on the cob into 4 chunks. Fill a pot with cold water and a pinch of salt. Add in your sweet potato slices and corn. Cover the pot and bring up to the boil. Cook until tender. When they're done, let them cool down and set aside.

Time to get fishy. If your fish has it's skin on, de-skin the fish. Cut the fish into 2cm cubes. Save any fish edges that didn't quite make it into neat cubes. When you're done, place the cubes in a bowl and put in the fridge.

Slice your limes in half and squeeze out the juices. Top tip here: don't over-squeeze your limes as this will release the oil from the rinds and give your ceviche a bitter tart taste.

In a blender, blitz the lime juice with 1/4 of the red onion, celery, any excess fish fringes, a pinch of salt and pepper. Strain the liquid through a sieve and set aside.

Slice the rest of your red onion into very thin slices lengthways. Place in a sieve and run them under cold water for a minute. This should take a way some of their intensity. After, pat them dry in a kitchen towel.

Roughly chop the coriander and finely slice the red chilli. If you find a whole red chilli too spicy you can lower its intensity by removing the veins and seeds inside and soaking the rest in lukewarm water for a few minutes.

Assembly time. In a bowl combine your fish, red onion, lime dressing and some freshly chopped coriander (save some for garnish). All the fish to marinade in the juices for 3 minutes before serving. The lime juice will slightly cook the fish.

Serve your ceviche in a bowl with some coriander and chilli sprinkled on top. Add in your sweet potato slices and a chunk of corn per person. Don't forget to spoon in plenty of the lime dressing into each bowl. Enjoy.