Put the prawns, half the chopped chilli, half the coriander, the zest of 1 lime and half the juice in a bowl. Stir together gently and leave to marinate for 10 minutes.
In a separate bowl, mix the soy sauce, remaining chilli and coriander (reserving some to garnish), honey and the remaining lime juice together. Put the lentils, sliced avocado and radishes in a large bowl, then stir through the soy dressing.
Heat the sesame oil in a frying pan, then stir-fry the pak choi for 1-2 minutes until just wilted. Add the prawns along with the marinade for 1 minute to heat through.
Divide the lentil salad between 4 bowls, top with the prawns and pak choi and serve garnished with the remaining coriander.