Cut the fish into small, even cubes and remove any remaining skin, scales, or bones. Put aside.
Juice the lemons and limes into a large bowl.
Place the fish into the lemon and lime juice, and ensure all the flesh is covered by the juice. Cover the container and store in the fridge for about 20 to 30 minutes. Every 10 minutes, turn the fish to ensure it marinates and "cooks" fully.
While the fish is in the fridge, wash the sweet potatoes with a brush and steam for 30 minutes or until tender. When the potatoes are soft, remove from the steamer, peel, and cut into large pieces. Season with salt and pepper to taste.
Shuck corn cobs, cut in half, and boil until tender. Drizzle with olive oil and sprinkle with salt.
Heat canola oil in a large pot to 375 degrees.
Peel the plantain and cut in half, crosswise. Cut into very thin slices using a potato peeler or mandolin. Place the slices into the oil, and make sure they don’t touch. Fry for a few minutes or until crisp, carefully remove, and place them on a plate with paper towel to absorb excess oil. Sprinkle with salt to taste.
Wash and dice the habanero pepper. Peel and slice the red onion into thin circles. Finely chop the coriander. Grate the ginger.
Remove the ceviche from the refrigerator – you'll know it'd done when the fish is opaque and flaky. Add onion, habanero, and coriander, ginger, and salt to taste. Cover the ceviche and chill in the fridge for 10 minutes.
Remove the ceviche from the refrigerator and place in cups or small plates. Garnish with some fresh coriander.
Serve ceviche alongside plantain chips, corn, and sweet potatoes and sprinkle with a little chili powder. Enjoy!