Rinse quinoa under cold running water for at least 30 seconds. Put rinsed quinoa in a medium pot with 2 cups of water and bring to a boil. Once it boils, reduce heat to low, put a lid on and simmer for 15-20 minutes or until all of the water is absorbed. If you are starting with precooked quinoa, it will be about 3 1/2 cups, cooked.
Meanwhile, in a large non stick skillet, sauté onion, carrot and celery for 3-4 minutes add a tablespoon of water if things start sticking to the pan. Next, add the red bell pepper and continue sautéing 2-3 minutes or until the carrots are tender.
While the vegetables are sautéing, in a small bowl, combine soy sauce, agave, rice vinegar, onion and garlic powder and ground ginger and stir to combine.
Add the peas, green beans and sauce mixture into the skillet and cook for 1 minute to defrost the vegetables. Next add the pineapple and stir to combine. Finally, add all of the cooked quinoa and fold the mixture until everything is evenly distributed.