Combine the first six ingredients in a bowl; add the prawns and turn to coat. Marinate 30 minutes. Place the sauce ingredients in a food processor; puree. Transfer to a bowl and store in the fridge until the prawns are ready. Heat a large, non-stick skillet over medium-high. Add the prawns and its marinade. Cook the prawns 1 to 2 minutes per side, or until just cooked through. Arrange on a platter with the bowl of sauce. Garnish with lemon wedges and serve.