Bon Appetit offers a recipe for Peruvian ceviche with ingredients such as sweet potato, corn, white fish, red onion and spicy peppers. The recipe suggests using fluke, flounder or sole fillets. The recipe is available at BonAppetit.com.
Start by making the leche de tigre marinating liquid. Puree 2/3 cup of fresh lime juice with 2 smashed garlic cloves, 1 tablespoon of chopped fresh cilantro leaves, 1/2 of a seeded and halved habanero or ají limo chili, and 4 large ice cubes until smooth. Add 1/2 chopped small red onion, and pulse a few more times. Strain the liquid through a mesh sieve into a medium bowl. Optionally stir in 1/2 cup of bottled clam juice, season with salt, cover and set aside in a refrigerator.
In a large pot with a steamer basket, add 1 inch of water, and bring to a boil. Add a small sweet potato to the pot, cover and cook until fork tender. Transfer the cooked potato to a plate, add more water to the pot if necessary, bring to a boil and steam a husked ear of corn, covered, for a few minutes until crisp-tender. Remove to a plate.
Scoop balls out of the steamed potato, and cut the corn from the cob, setting them in separate small bowls. Rub the inside of a large bowl with a cut chili, and place 1 pound of 1/2-inch cubed fish pieces into the bowl, along with 2/3 of a small quartered and thinly-sliced red onion, the leche de tigre and 4 large ice cubes. Stir well, and marinate for two minutes before removing the ice cubes. Fold in the sweet potato balls and corn, and season with salt to taste. Serve in small bowls, and garnish with leche de tigre, sliced red onion and cilantro leaves.