Off the Fork: Fluke ceviche Shelter Island-style

Deep in the waters of Greenport Harbor, partially buried in the sandy bottom, are scores of large fish, brown on one side and white on the other. Call them fluke, summer flounder or doormats: these flat, bottom-dwelling fish with both eyes on the same side of their heads are ugly — and delicious.

They look a lot like the flounder that is plentiful in fish markets, but fluke are generally larger and are said to have a sweeter taste. How do you tell a fluke from a flounder without taking a bite?

“You can tell by the mouth,” says Candice Manwaring of Southold Fish Market. “Fluke have a long jaw and flounder have a ‘puppy mouth.’”

Long Island fluke is a local delicacy so prized that many fish caught commercially are sent to New York or Japan for use in sushi. But why let these tasty fish be shipped all over the world when we could be eating them right here? Break out the limes and sharpen your knives. It’s ceviche time.

Ceviche is a traditional method of preparing fresh fish with an acidic broth or marinade, such as lime juice, vinegar or bitter orange (naranja). The acidic broth causes the fish to become flaky and opaque, as if it had been cooked. Maricel Presilla, in her landmark book, “Gran Cocina Latina,” (W.W. Norton, 2012) devotes an entire chapter to “Cebiches,” describing the diversity of styles and traditions of this dish in Peru, Ecuador and Chile.

This recipe is an adaptation of Maricel Presilla’s instructions, using ingredients from Eastern Long Island. With the exception of the limes and the salt, everything you need for this dish is available now, from our waters and farms.

Local fluke and flounder are available at Southold Fish Market (Route 25 in Southold) and flounder is available on the Island at Commander Bob’s Fish Market, Commander Cody’s and Clark’s Fish House.

Ceviche Shelter Island-Style
Serves 4 as an appetizer
Preparation time: 30 minutes to chop and assemble, 15 minutes to “cook” in the marinade.
1 pound of fresh fluke or flounder filets
1 teaspoon sea salt
2 garlic cloves, crushed and diced
Marinade:
1 1/2 cups lime juice (8 to 10 limes)
1/2 red onion, sliced very thin
1 tablespoon cilantro
1 jalapeno pepper, tops and seeds removed and cut in half
Up to 4 ice cubes
Garnish:
1 ear of sweet corn, barely steamed, kernels cut off the cob
6 cherry tomatoes cut in half
1 teaspoon jalapeno, very thin half-moon slices
1. Briefly rinse and dry the fish. Run your fingers over the filets to check for bones and remove them. With a sharp knife, cut the filets into 1-inch pieces and put them in a shallow, non-metal dish. Add garlic and salt and set aside for 10 minutes.
2. In a non-reactive bowl, combine the lime juice, onion, cilantro and pepper halves. Add the ice cubes and as they melt into the lime juice/onion marinade, taste it for tartness and heat (from the peppers). When it is still very tart, remove the ice cubes and the jalapenos.
3. Pour the lime juice mixture over the fish and let it marinate for 10 to 15 minutes or until the fish is white and flaky.
4. Garnish with corn kernels, tomatoes and thinly sliced jalapeno.
5. Serve the ceviche family-style on a deep platter or spoon into individual serving dishes.