Preheat the coals for the grill. Season the corn with a drizzle of olive oil, salt and pepper. Place the corn on the grill and cook for 2 minutes on all sides. Remove from the grill and cool completely. Using a sharp knife, remove the corn from the cob. Put the egg, garlic, lemon juice, parsley, and green onions in a food processor and puree for 15 seconds. With the processor running, pour the oil through the feed tube in a steady stream. Add the cayenne, mustard, and salt and pulse once or twice to blend. Cover and let sit for 1 hour in the refrigerator before using. (Best if used within 24 hours.) In a mixing bowl, toss the vegetables with olive oil. Season with salt and pepper. Place the vegetables on the grill and cook for 2 to 3 minutes on each side. Remove from the grill and cool. Small dice all of the vegetables. Place the vegetables back in the mixing bowl and toss with the cilantro. Set aside. Season both sides of the fillets with olive oil, salt and pepper. Place the fish on the grill and cook for 4 minutes on each side. Spread each half of the rolls with the butter. Place the rolls, butter side down on the grill and cook for 1 minute on each side. To serve, spread both sides of the bread with the tarter sauce. Place the fish fillets between the two slices of each roll. Spoon the relish over the fish and serve.
Yields: 4 servings