Roast the chopped walnuts in a pan without fat, set aside and let cool.
In the meantime, cut the washed rhubarb stalks unpeeled into approx. 1 cm thick slices and mix with the rest of the ingredients in the pot. Heat the mixture while stirring and let it simmer for 5 minutes. Remove the cinnamon stick and season with salt and cayenne pepper if necessary. Immediately fill into prepared, sterilized jars and turn upside down for 5 minutes.
You can let the fruit mixture soak for a few hours before cooking if you don`t want the chutney to be quite as chunky.
Goes well with cheese, grilled, pan-fried or simply spooned out of the glass.