1. Put the couscous into a bowl. Remove the seeds from the chilli and crush or chop and add to the couscous. Pour over the hot stock and leave to stand for 15 minutes until the stock has been absorbed. Fork through to break up the grains.

2.Meanwhile, heat the oil in a frying pan over a medium heat and cook the onion until softened. Add the carrot and courgette and cook for 5 minutes. Cool slightly and add the chestnuts, breaking up any large pieces, add the couscous, egg, herbs and seasoning. Mix well.

3.Divide the mixture into 8 and firmly press into burger shapes. Chill until ready to serve. (This will help to firm up the mixture and avoid breaking when cooking)

4.Before grilling on a prepared barbecue, brush the burgers with oil, cook for about 15 minutes, turning carefully.

5.Serve with toasted baps, salad and relish.