In a large saucepan, bring water to a boil. Add quinoa. Reduce heat; simmer, covered, 12-14 minutes or until liquid is absorbed. Remove from heat; fluff with a fork. Cool., In a large bowl, combine romaine, beans, mandarin oranges, cucumber, pistachios, onion and cooled quinoa. In a small bowl, finely grate zest from orange. Cut orange crosswise in half; squeeze juice from orange and add to zest. Whisk in oil, salt and pepper. Drizzle over salad; toss to coat.