In a bowl, toss the onion and peppers with the oil. Heat a large griddle pan and scatter in the vegetables. Cook for 5-6 minutes over a medium heat, turning until charred and slightly softened. Sprinkle with the Cajun seasoning and lemon juice, add the beef and stir. Cook for a further 3-4 minutes until piping hot.
Meanwhile, warm the tortillas according to the pack instructions. To serve, spoon the beef mixture onto the wraps and dollop with salsa and soured cream. Scatter over the coriander, roll and eat.