Heat the oil in large non-stick frying pan over a high heat. Fry the onion and pepper until the veg softens and has started to colour and char at the edges. Scoop out of the pan then add the prawns and another splash of oil. Fry until just pink then add all the spices and toss. Return the onion and pepper to heat through. Serve with warm tortillas, soured cream, guacamole and hot sauce.