To toast pecans, put on a cookie sheet in roast in oven at 350°F for about 10 minutes, turning once. Once cooled, put into a ziplock plastic bag and once sealed, use a rolling pin or meat tenderizer to chop the pecans. In a large saucepan, bring the 2 cups of water to a boil. Add the barley, cover and simmer for about 45 minutes. Remove from heat and let stand for approximately 5 minutes. Add the toasted pecans and green onions, and serve immediately alongside the fish.