Preheat a char grill or barbeque on medium high. When hot, place the slices of bread on the grill. Cook for 2-3 minutes on each side until charred and golden.
Take off heat then rub a garlic clove on one side of the bread. Set aside on a rack to cool.
In a large bowl, combine the prawns, lemon juice, capers, red onion, cherry tomatoes and olive oil. Season to taste then spoon mixture over the prepared charred bread. Garnish with rocket leaves and extra wedges of lemon.