Cook the beans in the boiling salted water in a large covered saucepan over moderate heat 10 to 12 minutes until tender. Meanwhile, place the garlic and coriander in a large heatproof bowl. As soon as the beans are done, drain well, return to moderate heat, and shake the pan 30 to 40 seconds to take out all the excess moisture. Place the hot beans on top of the garlic and coriander and let stand 10 minutes. Add 5 tablespoons of the olive oil and toss well to mix; cover and marinate in the refrigerator 3 to 4 hours, or better if overnight.
About 45 minutes before serving, bring the beans from the refrigerator and let stand still covered, on the counter. Just before serving, add the lemon juice, 3 tablespoons of the vinegar, and the pepper. Toss well, and add more vinegar, olive oil, salt, and pepper, if needed. Serve as an accompaniment to pork, poultry, veal, or beef.
Recipe courtesy of Jean Anderson