Heat over medium heat until bubbling, then cover and reduce heat to low. Cook for about 15 minutes or until all the water is absorbed.While your quinoa is cooking, get out and wash your green onions and tomatoes. Chop them roughly.Chop a lemon in half and squeeze one half's juice into a bowl, picking out the seeds.
Let your quinoa cool. A little warm is fine.
Add olive oil, lemon juice, and tomatoes and green onions to the pan. Stir.