There are lots of recipes floating around the internet, and a few available in older cookbooks. This is the exact recipe we used, and it worked for us. Robert picked a bucket of flowers, and we pulled all of the yellow petals out of the flower head. We had to remove the green bits, as they seem to be bitter. Picking the petals is a time-consuming, shoulder-aching, and finger-staining job, but the jelly is so tasty, with a deep floral honey flavor that it is all worth it in the end.
This recipe is available in our book, available Spring 2016.