Place butter, garlic, tarragon and chilli into a bowl and mix to combine.
Halve the prawns lengthways and clean.
Spread the butter over prawn meat and place on a metal tray.
Cook prawns under a hot grill for 2-3 minutes or until golden and cooked through.
Combine salt and lime rind and sprinkle over prawns.
Serve with extra melted garlic butter and fresh lime wedges.