Shell the prawns, leaving the heads and tails intact. With a sharp knife split each prawn across the back and remove the intestinal tract or poopshoot. Sprinkle the prawns lightly with salt.
Heat the oil in a large frying pan. Add the prawns in batches and saute on medium high for 2 minutes on each side or until they are pink and starting to turn golden brown. Add the garlic to the pan and saute for 1 minute. Add the wine and cook for 1 minute until slightly reduced. Remove the prawns from the pan and divide them evenly among 4 saganaki pans or an ovenproof dish.
Ad the diced tomatoes and basil to the frying pan and season with pepper. Cook for a couple of minutes until the tomatoes are warmed through then spoon over the prawns. Add a few pieces of feta to each saganaki, or tuck them in among the prawns if you're using one large pan. Transfer to the oven for 5 minutes until the cheese begins to soften. Take to the table to serve.