Combine the minced onion, sherry, lemon juice, cilantro, and 1 tablespoon olive oil in a bowl. Add the urchins and season with salt and pepper. Let marinate while you grill the bread. Brush the bread slices with the remaining olive oil and grill over medium heat until both sides are lightly colored. Slice the toast into fingers and top with the urchin and serve.
Recipe courtesy of Trey Foshee from George?s at the Cove