Using a pair of kitchen scissors, snip off the long, curly feelers and front legs. Using a sharp knife cut along the back of the prawns but not through the prawn. Open the prawn up like a butterfly and press it down gently to flatten. Rinse and remove the intestinal tract. Skewer prawns from head to tail.
Preheat BBQ grill to medium heat. In a food processor, combine garlic, parsley, butter, lime zest and juice together into a coarse paste. Coat prawns with paste and season. Place on preheated BBQ grill for 2-3 mins per side or until they turn an opaque pink colour and are lightly charred. Serve warm with a squeeze of lime.