Bring water, orzo, and salt to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until orzo is tender, 20 to 25 minutes.
Rinse orzo under cold water and scrape into a large bowl. Let cool for 20 minutes.
Stir in green onions, celery, cranberries, lemon juice, sesame oil, vinegar, olive oil, and cayenne pepper. Let stand at room temperature until flavors blend, about 1 hour. Stir in pecans and cilantro before serving.
