Place the conch between 2 sheets of heavy-duty plastic wrap, and pound to a 1/2-inch thickness using a meat mallet or rolling pin. Cut conch into 1/4-inch-wide strips. (If using scallops, heat oil in a large nonstick skillet over medium-high heat. Add scallops; cook 5 minutes, and drain.)
Combine conch or scallops and the remaining ingredients in a large bowl; cover and chill for at least 1 hour.