Heat the oil in a pan. Sauté the shallot and garlic for approx. 3 mins. Add the peach and all the other ingredients up to and including the salt, sauté briefly. Add the vinegar, cover and simmer for approx. 10 mins. Puree the dip until smooth, leave to cool.
To poach the prawns
Bring the salted water to the boil with the rosemary, bay leaf, lemon zest and juice, cook for approx. 5 mins. Add the prawn tails, remove the pan from the heat, leave to infuse for approx. 3 mins. Remove the prawn tails, refresh briefly in ice-cold water, drain.
Fill a platter with ice cubes. Arrange the prawns on top, season with salt, serve with the dip and lemon wedges.