At least 1 hour before grilling, soak plank in enough water to cover. Weight down plank to keep it submerged during soaking. Drain plank.
Thaw swordfish, if frozen. Rinse swordfish; pat dry with paper towels.
For marinade, in a small bowl, stir together olive oil, lemon peel, lemon juice, oregano, garlic, salt, and pepper. Brush marinade over swordfish. Place swordfish on a plate. Cover and chill for 1 hour.
For a charcoal grill, place plank on the grill rack directly over medium coals; heat about 5 minutes or until plank begins to crackle and smoke. Place swordfish on plank. Cover; grill swordfish for 15 to 20 minutes or until fish flakes easily when tested with a fork. (For a gas grill, preheat grill. Reduce heat to medium. Grill swordfish as above.)
Serve swordfish with Greek Orzo Salad and, if desired, lemon wedges. Makes 4 servings.
Greek Orzo Salad
Cook dry orzo according to package directions; drain. Rinse with cold water and drain again. In a medium bowl, combine orzo, cucumber, green onion, olive oil, lemon juice, salt, and pepper. Cover and chill for at least 30 minutes. Just before serving, stir in spinach leaves, grape tomatoes, feta cheese, and fresh oregano. Season to taste with salt and pepper.