Barley and Corn Salad with Basil Chive Dressing

Bring 2 cups water with 1/4 teaspoon salt to a boil in a 1 1/2-quart saucepan. Stir in barley, then reduce heat and simmer, covered, until barley is tender, about 10 minutes. While barley simmers, blanch corn in a 1 1/2- to 2 1/2-quart saucepan of boiling water 1 minute, then drain in a large sieve and rinse under cold running water to stop cooking. Drain again and pat dry, then transfer to a large bowl. Remove barley from heat (when tender) and let stand, covered, 5 minutes. While barley stands, pulse oil, basil, chives, vinegar, sugar, pepper, remaining tablespoon water, and remaining 1/2 teaspoon salt in a blender until herbs are finely chopped. Drain barley well in large sieve and add to corn in bowl, then add endives and dressing, tossing to combine.