-
1
Bring a large saucepan of water to a boil, add the sweet potato, turn down the heat, and gently simmer 30 to 35 minutes, or until just cooked through but still slightly firm. A few minutes before the sweet potato is done, add the corn and simmer 5 to 7 minutes, or until cooked through. Remove the ears, cool, and cut the corn from the cob. Cool, peel, and slice the sweet potato. To mellow the flavor of the sliced onions, soak them in a bowl of ice water for 10 minutes, then drain.
-
2
To make the
-
3
(sauce), place the flounder scraps in a large glass bowl along with the lime juice, half of the red onion slices, the ginger, garlic, celery, and two-thirds of the sliced chiles. Set this mixture aside for 20 to 30 minutes, then pass through a fine-mesh strainer into a bowl, pressing firmly on the fish, onion, and aromatics to release their flavorful liquid, then discard everything but the strained liquid. Season to taste with salt.
-
4
To prepare the fish for the ceviche, cut the squared off flounder pieces into even strips, 2 to 4 inches long and 1/4-inch thick. Cut these strips in half, and place them in a medium-sized glass bowl set in a larger bowl filled with ice. This will keep the fish cold. Sprinkle the fish with the 2 teaspoons (16 g) kosher salt, and stir several times to coat evenly. Let this mixture sit for 20 minutes, gently stirring every few minutes to the salt will penetrate and season the fish.
-
5
Add the remaining one-third sliced chile, the remaining one-half red onion, and the cilantro to the fish, and stir to combine. Slowly add the
-
6
, stirring several times. Pour the ceviche into a serving bowl, and serve with the sweet potato slices and a mound of the corn on the side.
