Peel the prawns. Discard the shells or reserve for another application. Lay the prawns onto paper towel to dry.
Heat the shellfish oil and butter in a large frying pan so that the butter melts and begins to bubble. Reduce the heat to low, add the prawns and stir gently to coat in the oil. Sauté gently for 1 minute, add the tarragon and season with salt and pepper. Drain the prawns and k