Opuntia species, the Prickly Pears

The Opuntia cacti are in flower during July and creating quite a display of fiery colours; yellows, reds and peachy hues in our Arid Garden.  After flowering we await the Prickly Pear fruit, a spiny delicacy that our chefs make safe in edulis and present as a rare epicurian delight.  Where else can you eat home grown Prickly Pears in the UK?