Combine olive oil, garlic, parsley and salt in a large shallow bowl. Add the pre-washed, patted dry seafood to the oil mixture to coat evenly. Cover and refrigerate for 15 minutes to marinate.While the seafood is marinading, prepare the salad and dressing; wash and dry lettuce mix ad place into serving bowl/s. Whisk the yogurt, garlic, parsley and lemon juice in a small jug/bowl. Season with salt to your tastes.Preheat the barbecue (or grill). Cook the salmon first; both sides until seared and cooked to your liking (about 4 minutes either side). Set aside onto a warmed plate. Add the prawns and calamari rings; cook for 2-3 minutes, turning occasionally or until just cooked. Transfer to plate.Top the salad leaves with the seafood; drizzle with dressing and lemon juice; serve with lemon wedges.