After some brief internet research, I discovered that they needed to be podded, blanched and then possibly shelled. Which was a soothing activity to do in the early evening.
I ended up with surprisingly small pile of beans. I only peeled the big ones - partly because that was what the instructions said, and partly because I am lazy. Limes and Lycopene had some useful info. In the end, I blanched some flat beans, and steamed some asparagus, and called the whole thing salad. Dressed with extra virgin olive oil, cracked pepper and lemon juice, it was a nice dish that said 'Yay for summer!'