Heat the butter and oil in a wide skillet set over medium/high heat. Add prawns and garlic and cook until the prawns have turned pink and are just cooked through, about 2 to 3 minutes. Remove the prawns from the skillet and set on a plate.
Add the Pernod and saffron to the skillet and bring to a simmer. Simmer until the Pernod has been reduced by half. Add the whipping cream and cayenne, bring back to a simmer and reduce until a lightly thickened sauce forms. Season with salt and pepper and stir in the parsley. Return the prawns to the skillet and heat for about 1 minute before serving.