Dragon’s tongues?
Just when I was suffering green-bean fatigue (big bags, three weeks in a row), these variegated beauties showed up in my sharebox yesterday. Purple dapples on a yellow base, they taste more like wax beans than classic haricots verts—and when you cook them, the purple fades away (mostly), revealing bleached, pearlescent pods.
Holy Mother of Dragons. Fiercely sweet, surprisingly tender, but with plenty of backbone, these’ll make you forget every boring, starchy, blah-bean you’ve ever had. I have no idea if it’ll work, but I’ve set aside a handful of shells to dry so that I can try to grow a row of them myself next spring.
As for prep, keep it simple and unsullied.
Either eat them raw (when truly fresh, the shells are succulent and the seeds nutty-sweet) or slightly steamed.
After trimming the ends (which probably isn’t even necessary), I steamed mine for about four minutes, then served them with a tiny bit of of butter (a quality olive oil would be just as good), a sprinkling of sea salt, and a few slivers of basil. That’s it. Powerful. Tender. A force for good in this world.
Boxing Day 
Are these the beans I have seen Jamie Oliver use a “bean stripping tool” on, then dress with butter olive oil S&P and serve just like a pasta?
Not sure what that is. I’ve used a vegetable peeler to shave ribbons of zucchini to treat like pasta (works and tastes great). Never heard of that with beans, but I’ll check it out. These really do need very little adornment, though.