Roselle is a member of the hibiscus family that is widely grown as a food in several parts of the world, including in the Caribbean, Africa, and Asia. In some places, the tangy leaves are eaten in stir-fries, curries and so on. This is very much a new plant for us and we’re still learning about how to grow it and how to use it. So far we’ve not grown it for the leaves but rather for the bright red calyxes that grow around the seed pod after the rest of the flower falls off. The calyxes also have a tangy, slightly citrusy flavour.
Again, we’re still very much learning, but I know enough to know that you can make some pretty amazing beverages from the calyxes, as well as an absolutely marvelous spiced sauce or jam that serves a similar role as cranberry sauce (and roselle has sometimes been called the “Florida cranberry”).
I won’t say much more since I’m hardly an authority here, but rather I’ll direct you to the links in the next paragraph. I’ll just note one more thing: if you buy fresh roselle, you’ll likely need to remove the seed pods from inside the calyxes so expect to spend some time doing that and expect to lose about half the weight of the roselle that you started with.
For further information, check out these articles by from the University of Florida and Mother Earth News. Whole Natural Kitchen from Australia has a nice, well-illustrated piece about making roselle jam. Edible Northeast Florida has a recipe for a spiced jam.