Preheat a barbecue or grill plate over a high heat.
Peel and devein the prawns, leaving the tails intact. Brush the bread and prawns with oil, rub with garlic and season with salt and pepper. Cook bread for 2-3 minutes each side or until bread is charred then warm prawns in pan.
Place cucumber, onion, tomatoes, prawns and bread into a bowl, season with salt and pepper and pour over dressing.
Toss to combine and allow to stand for 10-15 minutes. Top with fresh basil to serve.
Place vinegar, oil and fennel seeds into a small bowl and mix to combine.