Place peeled prawns in a medium bowl with 2 teaspoons of lemon zest and mix to combine.
Heat 1 tablespoon of oil in a small fry pan over a high heat. Add bread and pan fry till crispy. Remove from frying pan and place on a paper towel-lined plate.
Brush prawns with remaining oil. Heat a grill pan over a high heat. Add prawns, cook for 1-2 minutes on each side until cooked. Remove from pan.
Place rocket leaves and remaining lemon zest into a bowl and drizzle with extra olive oil and season with salt and pepper toss gently to combine
To serve, place tomatoes, bread and rocket in the centre of a plate. Arrange prawns on top.