Whisk first 5 ingredients in bowl to blend, and then set aside. Arrange lettuce on a large platter, or on 4 individual serving plates. Top decoratively with remaining ingredients. Drizzle the dressing over to moisten. Serve any remaining dressing separately.
Note: To blanch the green beans, cook in boiling water 1-2 minutes. Drain, cool in cold water, and then drain again. Nicoise olives are sold in the deli department.