Mix the oil, lime juice, garlic, chilli and a dash of Tabasco. Stir in the prawns and set aside for 5 mins. Heat the tacos according to pack instructions.
Tip the prawns and the marinade into a frying pan and fry for 2 mins until the prawns turn pink and are cooked through. Spoon into the warm tacos, add some lettuce and serve with guacamole and soured cream.