Preparation Cook beans in a 6-quart pot of boiling salted water, uncovered, until tender, 4 to 6 minutes. Drain in a colander. Heat oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then sauté garlic, stirring, until golden, about 1 minute. Add beans, arugula, zest, salt, and pepper and cook, tossing, until arugula is wilted, about 2 minutes.
Preparation Cook beans in a 6-quart pot of boiling salted water, uncovered, until tender, 4 to 6 minutes. Drain in a colander. Heat oil in a 12-inch heavy skillet over moderately high heat until hot but not smoking, then sauté garlic, stirring, until golden, about 1 minute. Add beans, arugula, zest, salt, and pepper and cook, tossing, until arugula is wilted, about 2 minutes.