Heat the oil in a frying pan and gently fry the onion until soft, about 10 minutes. Stir in the chipotle paste and the chicken to warm through.
Heat the rice following pack instructions and warm through the kidney beans in their liquid in a small pan. Drain the beans and fold in the cooked rice, with half the lime juice and half the coriander.
Mix the remaining coriander and lime juice with the avocado, mashing it well with some seasoning.
Heat the wraps individually in a dry frying pan to warm through, or warm in the microwave for 5-10 seconds.
Divide the rice and beans between the warmed wraps, piling the mixture into the middle of each one. Lay the chicken on top, then add a spoon each of the avocado, salsa, cheddar and soured cream, if using. Don’t overfill the wraps or they will be difficult to close.
With each wrap, fold over two ends to cover the filling, then carefully roll over and tuck the ends under to make a thick sausage shape with the folds on the base. Keep the prepared ones warm in a low oven as you work. Cut in half, on a diagonal, to serve.