Skin the seabass fillets, if necessary. Cut into large dice, and keep refrigerated until needed.
Top and tail the sweet potatoes, and cut into 2cm-thick slices. Cook in plenty of salted, boiling water until tender, about 8-10 minutes. Drain, and chill until needed.
Shuck the corn cobs. Boil or steam until tender, about 5-8 minutes. Drain and chill until needed. When ready, slice into chunky slices.
Top and tail the red onion, and thinly slice from top to bottom. Soak in cold water until needed.
For the leche de tigre:
Zest and juice the limes.
Trim the woody tail off of the chilli's, split in half. Remove the seeds from the chilli's, but keep the spongy rib.
Pick the leaves from the coriander stalks, and set aside. Do not discard the stalks! Keep a few whole leaves for garnish, and finely chop the rest.
Smash and peel the garlic cloves.
Peel the ginger, and thinly slice against the grain.
Place the lime juice and zest, chilli, coriander stalks, garlic cloves, ginger and celery stalk in a blender, and blitz until smooth. Add salt and pepper to taste, then pass through a fine sieve to remove any fibre or bits.
When ready to serve, toss the fish in the leche de tigre, along with the chopped coriander and drained red onion slices.
Mound the fish in the centre of a plate, and garnish with a few slices of sweet potato and corn on the cob. Finish with a few whole coriander leaves and if you can find them corn nuts.
Any remaining leche de tigre should be drizzled on top.
«Any fish can be used for ceviche, but it should be firm-fleshed and fresh. Sea foods such as squid, prawns and scallops are also lovely. If you cannot find corn nuts, leave them out or garnish with popped corn.»