Rub the lime juice in the swordfish and marinate just for 15 minutes; season with salt and pepper. Parboil or cook corn in the microwave oven for a minute. Pat the corn dry, transfer it to a mixing bowl and mix with the tomatoes. In a small bowl combine the ground cumin, olive oil and lime juice; season with salt and pepper. Toss this with corn and tomatoes and adjust seasoning add more oil or lime juice according to taste.
Get an indoor stovetop grill nice and hot. Brush grill with vegetable oil. Place swordfish on grill and cook for 4 to 5 minutes a side just until cooked through but still moist on the inside (or roast at 500 degrees for 7 minutes). Season with salt and pepper. Toss the fresh mint and chives with the corn and tomato topping, mix well and spoon some over the fish and some around it as well.