Bring two cups of water to a boil. Add the quinoa and bring back to a boil. Lower the heat to medium, cover the pan, and simmer for 12 minutes. Turn off the heat and rest, covered for 15 minutes. Remove from the pan and spread onto a plate to cool.
In a wok or frying pan, heat the sesame oil, add the onions, and fry on medium heat until transparent. Add the ginger and garlic and cook for one minute.
Add the carrots, frying for 3 minutes, then the broccoli, cooking for 2 minutes. Stir in the shiitake mushrooms, and pour in the tamari and water mixture, making sure the vegetables are evenly coated.
Cover and steam for 2 minutes. Turn off heat.
In a bowl, mix the cooled quinoa with the vegetables. Add the orange juice, and fluff it through. Chill for an hour or serve immediately.