My advice is: avoid big bumpy beans.
"Whatever recipe you choose for your beans, always give them a preliminary blanching in a very large kettle of rapidly boiling salted water. Depending on what you plan to do to them later, boil them either until tender or until almost tender, and drain immediately. This essential step in the French art of bean cookery always produces a fine, fresh, green bean of perfect texture and flavor."
When your pot of water is boiling vigorously,
"A handful at a time, drop the beans into the rapidly boiling salted water. Bring the water back to the boil as quickly as possible, and boil the beans slowly, uncovered, for 10 to 15 minutes; test the beans frequently after 8 minutes by eating one. A well cooked bean should be tender, but still retain the slightest suggestion of crunchiness. Drain the beans as soon as they are done."
I find that 8 minutes is enough for fresh young beans. I have a light-weight skillet ready beside the boiling water. Using a slotted spoon, I spoon the beans into the skillet and place the skillet over low heat. Julia Child explains it as follows:
"Turn the beans into a large, heavy-bottomed saucepan and toss them gently over moderately high heat by flipping the pan, not by stirring them. This will evaporate their moisture in 2 to 3 minutes. "
When the beans are dry and still hot, I add a little butter and let it melt. The beans are now ready to serve. (If you would prefer to save the beans for the next day, do not add butter, but chill the beans, cover them and keep them in the refrigerator. They will keep well for 24 hours at which time you can either serve cold, or re-heat them.)
Happy Cooking,
Ruth Ann